is brain freeze good?

brain freeze is probably the best/easiest heroe to play. Build a pets deck

cat lady, chicken/fire chicken, zookeeper, fish imp, dolphin, kangaroo, locus swarm, pogo bouncer, nibble = all easily accesible non legendary/super rare

If you have add any of following super rares/legendaries: yeti, maniacal lauugh, sharktronic, gravedigger

Basically you'll use cat lady until you can biuld something strong with zookeepers.

All heroes have their own weaknesses and strengths.

Brain Freeze's strengths: Pet decks, Imp decks, Deadly + Frenyz, ect.  He's basically a Zoo/Aggro deck guy.

Brain Freeze's weaknesses: A lot of his cards are weak to Control.  Kabloom Control can kill his Pets, Solar Control can kill his Imps, and Solar/Smarty Control can Bounce/Destroy/Freeze his Gargantuars.  He's also quite weak to aggro.  But you should be good against a midrange deck, with all of his Deadly, Bouncing, and Locust Swarm.

Also, Wall-Knight makes an incredible strikethrough/healing deck.  He uses defensive plants to guard his strikethrough plants, then he uses Geyser and 2nd best Taco of All Time to stay in the game long enough to play heavy-hitters like Laser Bean and Cornucopia.  He's basically a Control god, like Solar Flare.