Replanted Steam Edition Bugs (& Possible Errors)
From what I can tell:
The flag is missing the extension after every wave (when the flag goes up, the pole is supposed to extend to the bottom of the level bar, as seen in GOTY edition)
After every level, the screen should fade into white, but instead the screen suddenly goes white and fades back to the regular screen before abruptly cutting to the next level / menu
Unsure if this is just me or the conditions I'm not hitting, but I've been unable to get the Pyromaniac achievement (using Potato Mine (x2 because of Imitator), Jalapeño, and Cherry Bomb)
Problems with a couple zombies clipping in pool levels (from what I can tell only when frozen)
After taking damage, the pumpkin is unable to be replaced with the wall-nut repair kit until it hits a certain damage threshold, so despite showing a state of damage, it won't let me replace it
The flag after the Zomboss battle can be seen in the eyes of the big helmet (also Zomboss' eyes remain slightly yellow post-battle, unlike the GOTY edition)
The Zen Garden tools don't show up on the cursor when in-use on other plants, unlike in other versions where clicking on the tools while in-use will provide a second copy to go with your cursor while the other one will destroy after use
Not having control over which garden you switch to in the Zen Garden (not a bug, but it's hindering to have to scroll through everything to get to the one you want, especially when there's a loading buffer between the Tree of Wisdom and the other gardens, whereas in versions such as Console Edition, you can click on which ever garden you would like)
Crazy Dave's shop always opens from the first page, when in other versions, opening his shop while in the Zen Garden always starts you on the Zen Garden page of his shop first
(Also not a bug, but) Very large text blocking the graphics of plants and objects in Crazy Dave's shop, when it only used to appear for seed upgrades and when sold out
When in it's very damaged (and about to explode) state, the catapult zombie's catapult will disappear, while the rest of the vehicle remains in-tact
The speed counter is visible from the loading in of the level until you reach the "Choose Your Plants!" menu, and when toggled will reset back to the default speed when the level starts
Pre-chosen seed packets by Crazy Dave will appear before the "Choose Your Plants!" UI has a chance to appear first
A section of the song "Grasswalk", and possibly others (I think I recall "Moongrains" doing this too), will play the dynamic track during a certain area of the song despite there being a lack of wave and actual dynamic audio, then will suddenly snap back to the original version without the dynamic audio
The seed packet for the pumpkin is different from the actual placed pumpkin, lacking the damage on both sides, leading to a rounded look
The sliding glass door in the Fog levels is closed, when in the other versions, it is open and shows a little peek into the player's home
The circular zombie head on the house (visible on the roof during the Day/Night levels), is only present in the mobile versions and not in the GOTY/Console versions, it is also missing from the title art of the home, leaving it out of place
(Unsure if this is a bug, but) The cabbage-pult can sometimes sport the Plants vs. Zombies 2 skin instead of the normal one
The "Huge Wave of Zombies" text is off-center on the Y-axis and isn't supposed to flash white (unless this is a design choice)
The "Final Wave" text is off-center on the Y-axis
The squash will not attack zombies behind it unless the zombie passes it while placed down
That's all I can recall for now!