Oh wow thanks, just realized that the web version wasn't updated, it was playing version 1.00 instead of the current 1.02. Just updated all versions to 1.03 with some quality of life changes.
Has for the upgrades, yes the goal is to eventually have each plant have different uses / skills. So you could have one that is close quarter and does a lot of damage, one that's super slow but shoots massive AoEs, one with a chain lightning that also puts enemies to sleep, etc... This is the system I'm currently working on and should be coming in the near future.