This game isn't that bad but it isn't that good either. This game could use a lot more work and some music to be added to it as well. Music sets mood and without mood the user becomes extremely bored really fast.
Another thing, graphics aren't everything. First try to have a story line instead of just racing. In fact this game isn't even racing... it just consists of trying to beat your old time. I've seen this tutorial around on the internet before that showed me exactly what your game is. Instead of copying the same idea as that person who created the tutorial just use some information from it and create your own game idea from it. It tends to get a lot more views and better comments than this one here.
Overall 6 / 10