They added the Zen Garden from the PC version and added new play types like puzzle where I have so far unlocked "i, zombie" and another mini game called "ZomBotany."
"i, zombie" is rad as you take you turn as the zombies attacking cardboard cut outs of the plants. "ZomBotany" is a mode where the zombies are fused with plants as they attack you.
There seem to be many other unlockables I can get by collecting tons of coins or I can outright purchase coins to unlock all this stuff. Cool feature, but makes me nervous as if my phone gets wiped it seems like ill lose all the unlocks? I don't know.