If another PvZ Shooter is made, what features should be added?

@TheSprinter85BFN might have been an experiment for straying from GW traditions such as no variants and a faster meta and tried finding replacements like legendary upgrades. Maybe they realized it had gone wrong and are making a GW3, but who knows.
I think the sprinting was a good addition, but was added wrong. Maybe have sprinting with a stamina bar and certain characters will be faster then others like in the GW games. I would prefer variants over the upgrade system for repeatability. The PVE is better in BFN but have a longer story line that isn't just completed in a day. Just something personal, but I prefer the GW1 character selection screenings its more appealing visually instead of just a portal or a simple blue screen. The sticker packs for GW games were better then the reward o tron. The selectable abilities were better too.

This will be a long list so I'll have to work on it first, but for a quick start; it would be GW3 and be based heavily on GW1 and 2, but with some of the BfN aspects that worked well. It would keep all the characters and add some more. We'd get all the old maps back, with any tweaks needed to the GW1 for the larger characters. Variants would be worked in so for example, instead of electric slide being the main character, it's be disco slide or something like that and electric slide would be a variant. Free roam regions would exist but have reasons to return so PopCap would get more value from the huge amount of work it must take to make them. We'd use BfN's upgrade system but we'd make sure none felt required like rapid fire for the foot soldier. The economy would function more like GW or GW2 as the 2 worst things about BfN are functionality of the core engine (moving, shooting, lag issues, etc.), and the economy.

There would be a lot of things that I would want in a new shooter, I am going to make a list here of what I would like implemented from GW2 and BfN, and my list assumes that another shooter is coming in the future, however it will be the final one we ever got:

From GW2: Variants, Damage drop-off, Ops content, Similar Weekly Modes In the Mystery Portal, Community Challenges, Torchwood, Hovergoat, Infinity Time, The way Rux operated in this game, Alternate abilities, Sticker Shop, BOSS HUNTS (just saying).

From BfN: The Upgrade System, the new characters, Legendary Upgrades, Prize Maps, Daily/Weekly/Character Challenges, Rux (reworked), Free-roam regions and content, Gnomes and Gnome Activities (expanded), Shields, Rando Ops, Battle Arena (ranked?), Hunts (like the pie hunt back from last November).

Obviously there is more I would like than that, and there is stuff I would like added, but this is what I have so far.

Thanks for all of your replies!

copy gw1/gw2 play style, axe story mode completely in favor of multiplayer, copy fortnite free with paid seasons.  Make a solo vanquish mode so I can kill everyone and plants can kill plants, zombies can kill zombies.

They need free at launch and make money from customs and season pass so they maintain an operational budget for updating content and fixing bugs...most games doing this now so you don't have that front heavy influx of money where they leave a skeleton crew for updates across 50 random games...it doesn't work.  EA still operating on bleed em dry up front and watch the game whither.

New updates and content keep players around otherwise they all die quickly.

@Gormey agreed. If they're going for a long term continuous update cycle like many modern multiplayer games are these days, they need to embrace the F2P model and have stuff to buy over time, and without emphasizing FOMO so much. I'm not a huge fan of F2P games but if it's going to maintain a large playerbase and keep people interested, it can work. I would prefer a 'box price' only and that's it, but that's difficult to do with a game that is intended to keep people playing, and that means more content which needs to be financially supported to be viable. 

Normally I don't like games as a service at all, but if the next PvZ shooter is going to last for a few years like Destiny or Warframe, I'd be behind it as long as it all works right. Get the core shooting and moving done correctly first, then do the other stuff. They really need to get the economy in a better state, as BfN's was messy and frustrating. Don't make people feel forced to spend, but instead make a compelling experience so that we want to support the game, it sure worked in GW and GW2! 

As I said, this would be a long list, but here goes:

• Above all else, get the core functions as smooth and accurate as possible! No more weird aim glitches, or bad hit registration or lag issues for folks, and get bugs hammered down more quickly. This is one of the 2 core problems with BfN that really hurt the game.
• The second major problem is to get an economy that doesn't rely on FOMO and doesn't make currencies obsolete. I'm especially looking at rainbow stars and coins from BfN here. GW1 only had coins really, although an argument could be made that challenge stars were a coin of sorts as well and became obsolete once you maxed all classes but coins always felt good to get. GW2 added stars and rainbow stars but even at max rank and having the crown and all the decorations, you can convert those stars into rainbow stars and buy the chests at the town hall when it's open. That's not perfect but it never feels bad to earn coins, stars, or rainbow stars. The only bad thing about GW2's economy is gaining XP when level capped. BfN's economy hits a brick wall early on with coins and the regional currencies becoming largely useless, and the over reliance on rainbow stars via RL money with only a pittance being earnable in game. Between this and the above point, a lot of people left the game in frustration. Get these 2 right first, and the game will do better than BfN has.
• Crossplay! Between all platforms. This would be a huge help for the community and also let us all play together! 
• Powerful and effective Anti-cheat. BfN has been much better about than either GW game, let's keep this up and even improve it if need be!
• Get the balance as solid as possible. All MP shooters have balance issues, especially as they add in new characters and weapons, but the 3 PvZ shooters have had a lot of balance problems. Get this as tuned as possible in the alpha/beta stages as possible and it'll be easier to keep that balance later. There will times of meta like every other MP shooter, but they need to be dealt with in a timely manner.
• Bring back all the maps from all GW1 and 2, with any adjustments needed to balance them and allow large characters to play on them, and yes, this includes both Garden Center and Aqua Center. BfN maps can work too but they need some tweaks, TT maps for example, need to have more maneuvering and flanking instead of almost every fight directly on the point. People have been asking for the GW1 maps in the newer games for years, so that would be a selling point to boot. New maps should also be added but the GW1 maps especially are a treasure trove!
• Keep BfN's upgrade system but make them more balanced and interesting. Some like rapid fire for the foot soldier are considered essential and that defeats the purpose of giving us choices. GW1's upgrades were all from packs and fixed per variant, GW2 had some variety for each variant as you leveled up, but BfN wins here, they just need to be tuned better.
• Keep all the characters and add more, but add variants back too. Not sure what to do with some like Iceburg lettuce but maybe the default for some characters could be elemental? I'd love a Space Cadet with a flame thrower weapon replacing her cosmo shot or a toxic Acorn/Oak (Poison Oak!). I especially want Berry Brigade to make an appearance!
• Give us all the old consumables back from GW and GW2 and add more as well. Give me my pirate barrel zombie, backup dancer zombie, and Laser Beans back!
• Make Ops more fun and challenging again. Ops in GW1 were rough and some of the challenges were obnoxious (take no damage at all was a pain for example), GW2 Ops are excellent, and BfN Ops just aren't all that great. I'd say to take the GW2 Ops formula, with the difficulty settings, multiple garden/graveyard locations, evacuation at the end, and add in some extra options; 5 or 10 waves, elite boss toggles (on, off, random), and so on. 
• Balance the bosses, and especially the elite bosses better to each other. For example, the elite disco boss is easy as long as people move to the gramophone, but the super squash can be rough. These can be further balanced in Ops based on the difficulty settings so that an elite boss on easy Ops is far easier than the same one on Crrraaazzzyyyy!
• More bosses. I love that we have more bosses in BfN, but I'd love to see even more added to increase variety and the return of the Giga-Gargantuar as well.
• Improved Giddy Park/Backyard Battleground. I prefer the GW2 main area as there are so many AI spawning on both sides and you can get some crazy fights going on with multiple players, bosses, champions, and so on. Maybe have our own private backyard battleground type area as our home, although larger than it was in GW2, and have some war torn public area where you could just jump in and battle with players and AI whenever you liked. It could also double as a lounge area where you could battle while waiting for a queue to pop. Maybe have events here as well! As for your personal area, I'd love to see a lot more places to customize it, and the prize map/season pass could have a lot of decorations to earn for that exact purpose.
• Free roam regions were a favorite of mine in BfN but once you finished them up, and zombie town center was especially quick as a chunk of that I already had done on plants town center, there's not much reason to go back. I'd say to add reasons to visit them again, maybe invasions, some PvP options-one side invades a zone and the other defends, special quests, and so on to liven them up. 
• For quests/challenges. I'd say to avoid specific character challenges and instead have more open ones; i.e. instead of '15 vanquishes as a Sunflower', have it be '15 vanquishes as a plant'. A mix of daily challenges and weekly quests would give short and medium term things to strive for and perhaps each season, we get other special things to do for rewards. For example, a Halloween event where you hunt down candy hidden randomly in the free roam regions and elsewhere you can find to but specific prizes and such. Think stuff like GW2's lawn of doom but more in depth.
• Animate Crazy Dave and Zomboss again. This is very minor, but GW2 Zomboss and Crazy Dave animated when they were sending you messages, in GW and BfN they don't. It's more enjoyable to have the animations.
• Add teleporters and turrets back. This one is more on the minor side, but I did enjoy the extra little bit of strategic depth these added. I'm not 100% worried if these didn't return, but I like what they add. Making turrets upgradeable like they were in GW1, would be an option.
• If it has a season pass or similar thing, don't fill it with so much fluff. All the victory slabs and punchers felt worthless as we can only use so few of them. So much fun art wasted feels bad. As for expressions and such, they at least could be used, I know the season pass/prize map needs a lot of stuff present to work but a few more interesting things would be better. How about decorations for your private backyard battleground? 
• Less toxic emotes. Part of BfN's problems has been how toxic the community has gotten. Taking the poop and similar emotes away would really help with the general feeling of higher toxicity in this game over the previous ones.
• XP should always do something. When at max level, earning XP should give something; coins most likely but maybe a level cap/reward system could help with player retention as well. And this also brings me too...
• All levels should feel useful. I actually enjoy unlocking stuff as I level up, as we do in GW2 and BfN, but the grandmaster levels all feel pointless and like they were put there just to add to the treadmill. Go ahead and have a lot of levels and ranks if you want, but make them all do something besides make that badge value tick up one point.
• Rework certain characters. This is subjective but I really don't enjoy Engineer in BfN at all as one example; double time feels mostly useless barring some narrow situations and the way he sits in the turret aura all game and spam concrete is an extremely dull playstyle and frustrating to play against.
• Support the game long term with new maps, more exciting mystery portals, community challenges, and new characters/variants. Keep working on balancing and crushing bugs as needed. This goes back to the economy as well, but expands upon that.
• Better promotion than BfN had. GW and GW2 had a ton of videos, I've been watching them again and they really made the games sound amazing and were amusing to boot. BfN just hasn't had that many and the sudden launch always felt weird to boot.
• Better communication. This is key. I'm positive now that the lack of communication was the incoming end of new content, but more open discussions would be great.
• Private matches need to be a thing, but bots need to be more like they are in GW2 instead of BfN and we need solo Ops back where we can play with bots. Also expand on options, like let us rando our private matches.
• Bring back modes. Mixed mode needs to be a thing again, but also I miss Taco Bandits, Capture the Taco, and Soil Survivors. All were great fun and even if you have to keep only CTT instead of taco bandits, that would be acceptable. 
• Battle Arena needs to be managed better. The concept of BA is really cool and I love seeing people having to play other characters rather than just playing a couple and ignoring the rest. This will work a lot better with a larger character pool for both sides to draw from.

I'm sure there's more than this, but this is my main wishlist. Basically, give us a game that works, feels fair, isn't plagued with microtransactions, is faithful to the IP of PvZ, and is fun to play with lots of options and reasons to keep playing!