Beat the game yesterday!
What a game. It's really fantastic, and man do I wish Sony would remaster the second game!
Though I have to say the plant bosses are badly designed. I got to the level 5 version of the optional one of the two, and died like seven times in a row. He keeps killing my flag bearer, and there's nothing I can do about it. The issue is mainly the part where when you interrupt his animations with a stagger, his releases some sleep gas. I can't evade that because it's random; it cannot be anticipated. So he does that, then jumps on my troops, killing them one-shot, and eventually he does that to my flag bearer, because as far as I know, I cannot order him to back off.