They unlock the final stage. :)
Recent community posts
Thanks for the replay and the review.
I am in this moment (well, in about 20 minutes, just got up) working on a completely new Jump'n'Run-Engine that allows for far more flexibility. in movement and all. The first game with it will be a little test-game, that I also use to implement and test new features. It will be a little puzzle-platformer.
But one of the games that are planned with it is "Battle Slut XXX" (which then obvioulsy will be a Metal Slug X homage) and a remake of Suicide Mission with good graphics and better gameplay.