First off, some people will load a game with moves and abilities and items that the players use throughout the game. This is OK, but to make it better, you could give them the items and abilities as they progress. If you didn't earn the moves in ED, would you like it as much? Next point, most people despise the default platform engine. It's simple to fix the bugs. When you press the jump button, use the function on the object (Input X or something) to ignore input from the jump button, stopping players from sticking to ceilings. When they hit the ground (I'd suggest using a detector), allow the jump button to work again. Use side detectors to push players away from walls so they won't get stuck. Simple as that. Final point, ability, item, and weapon variations. Gunner 3 was great, except for the fact that once you got certain new guns, there was no point in using the older ones. OK, but not excellent. Commando has better gun variation, because there are few guns that are better than others. In the case of abilities, don't make the kick better than the punch, don't make the double punch infinitely better than the single punch if you don't have to. If you use swords, then use someting like speed differences, elemental alignments, and certain moves that can only be performed with the right weapons. If you apply these tricks (which I write too much about) to your game, you can make it much better!

Cha!