Rayman has hell lot of greenery.

You could definitely give more details. You gave more explanation that it is probably unknown game than about the game itself. And only after few posts you say it is 2D platformer. See, you surely can give more details. What is about, what some parts of game looked like, do some drawing or something...

Hmm... Guimo?
http://www.mobygames.com/game/dos/guimo
I remember playing the shareware version, but I thought it was released on shareware discs on Brazil only...
At least there's a lot of green on it, I think I still have this game around somewhere...