My game is always getting slower or like stuck in the game. Yeah some one can think to reduce the pixeles of the objects but I want to know a better way to be faster and have more resolution. To be more specific, the tipe of game I'm doing is a guitar hero game and as you know in that kind of games it has a lot of notes that means a lot of objects so the game is slower and slower. So please I need help to find a way to make it faster. Please answer, I need opinions of the people that have an idea for this, I will really appreciate it.
Your performance is probably bound by your pixel shaders (fragment shaders in OpenGL lingo). To check if that's true, try removing some of the materials that involve pixel shaders (such as those using per-pixel lighting like bumped diffuse, etc). Also, remove fog if you have any.
If that doesn't work, the frame buffer could be struggling on whatever device you're using to test your game. Especially if you're rendering a lot of stuff to texture at screen resolution, before finally rendering to the screen. Might be another reason, but that's just my guesses -- try them out.