But the game play itself is decooupled from frame rate already, isn't it? Or does this really cause a slow down in form of slower moving entities? If so, you should change that anyway. As for the garbage collection...jPCT-AE itself tries to avoid garbage where possible. However, that doesn't mean that all methods are tweaked that way. It can very well be, that less common methods still produce more garbage then they actually have to. If you could identify where most of the garbage causing the collections is created and if that it inside the engine, then maybe i can do something about it. Also take care to use the getters that take filler variables where available, i.e. don't do getTranslation() but getTranslation(fillMe) where fillMe is a always the same instance.