the red flies that hover over your plants should be slower. i had a run ended because a fly hovered through all my defences without me noticing.
i know there is a zombie in pvz2 that acts this way but when that one hovers over the plants it slows down.
also i think a way to see what enemies and bosses you have seen (like the almanac from pvz) would be cool.
also also, i used the pokeball thing in that mage that freezes your babys and then realesed it and it carried that level, the next and it defeated the boss. maybe it could be nerfed, like maybe reducing the knockback. because the reason why it was so good was because it never got to move offscreen.
edit: i forgot to mention, this game is amazing