Help! can't download some games on my G6 Lite!

When i try to load some games on my g6, they are usually around 6-35 Mb at first download. and when i load a game onto the g6, it's usually
250-1024 mb big. but when i load some games on my G6, it starts out at 3.5 or so mb and when i get it on my g6, it is only 64 mb. Please help! i want to play some of these games!

I'm sorry, forgot to say what happens. the screen goes to title and when i try to start, it just goes to a black or white screen.