what new features would you like in lf2?

[A-Man]

The idea of a fourth button isn't bad at all IMO. One can use it for a heavy attack, for attacking with a weapon you're holding or maybe for grabbing. A developer should be able to not make use of the 4rth button if he wants, but supporting it would still be awesome nevertheless.

I liked the idea of taking the top left corner pixel for the colorkey.

Edit:

about falling opponent hit: how about making that a new body type? so only special itr types will be able to hit it.

A new bdy type? Why restrict yourself with LF2's coding mechanics? LF2 wasn't made to be modded in the first place. Here is an idea:
a "flag:" tag which can be fed one or multiple values. Only an itr and a bdy having the same flag would interact. That would be a pretty good farewell to all the special bdys we've been doing.