The game is lagging when you get an achievement, even in low quality. You should optimize your code before giving the possibility to turn off some features.
Please, if you want to be a game programmer this "game" is a test that you have to keep for yourself. When you will have a real idea you can submit it.
 "Vital Bloodshed"){kind=icon}
 "Toxers"){kind=icon}
 "TGM4"){kind=icon}
 "Space Conqueror V0.005"){kind=icon}
 "Warzone Castle Defence"){kind=icon}
 "Tracker-Tracks Everything"){kind=icon}
 "Minesweeper!"){kind=icon}