Game Concept…

Hey Guys, I am the owner of a new MacBook pro, and with it, I downloaded GameSalad, having spent most of time using stencylworks, and what not, I am now really enjoying Gamesalad, my game concept is one of reaction speed, I have four walls, you(the player) starts in the middle and as the wall turns a different color, you must move in that direction, with the wall spending less and less time on the different color, the level gets harder and eventually like tetras (unless you’re an expert) it will get to the stage where it is unmanageable… BUT I was thinking of a scoring system etc for it. Let me know what you think? I also had other ideas for another level, with maximum speed being achieved and seeing how long it takes you to slow down etc with different rules and obstacles stopping you … A timer based game, if anyone has any input? Let me know, Thanks…