it's a different game engine so it would make sense
it isn't flash anymore
No, it doesnt make sense. This game engine is much better optimized, meaning ii can run better on some older systems with ease.
Besides, its an issue other than game engine. Something on his computer must be preventing it from launching, and it shouldn't be the game.
But, just in case, did you try uninstalling it and re installing it, just to make sure its not just an installation error?