Congrats, you have made a fun game. Your problems are: the pink troll doll doesn't look good, especially when put alongside better art. The text color is also not readable enough(even in the title picture). But the biggest problem is that this game has to be downloaded and it is 633 MB, that's insane (it takes 5 min to download). I suggest you try to find out how to get the smallest possible size for an UE4 game.