#3 or #4 gets my preference, but I'm loving friendly and warm atmosphere in videogames, so that dictate my choice. Instead, *your* choice should be dictated by the atmosphere you want to create. Bright green is fine for younger (or nostalgic) audience who'd rather slice rabbites and pumpkins than zombies or freaky monsters.
At a second look, colours in #3 could be slightly over-burnt and #4 would be my final preference.
The new tree has definitely a more interesting volume and the smaller leaves imho work very well: they're better blending into a general shape and do no longer draw so much attention. I'll have to study how you managed to do that.