Red Flies(?) Will use their flying ability to go over spike traps which would not even hurt them, thus flying over the entire map scot free. Also they just bloody suck in general, they are much more OP than the pogo or flying zombies in PVZ, as those had simple counters, and could be hit while flying over plants.
Lobber babies are not that useful, and all are rather weak.
Poop pushed onto walls should damage them, but not literally push the whole line, without Sanguine Bond or spikes they just destroy everything as they hide behind other monsters, pushing everything off the map. Even if they are killed it is hard to fix the damage as it means replacing almost the whole line. RIP if it happens on multiple lines at once.
Please more slots, or the ability to get more. PVZ excelled in complexity later due to having lots of special enemies and lots of slots, that still limited the player. Having essentially 1 or 2 actually combat babies is just annoying as hell, usually I have a cheap one that gets replaced with the second more expensive one, or two that just fill one or two lines each. Also it makes gimmick babies basically unusable later, as shields and heart producers are required, and the later levels go too hard to have just one offensive baby.
Oh and perhaps they should be called familiars and not babies, as a literal pile of meat or spikes are not even babies at all.