For a first game, it's not that bad. Other people already mentioned not being able to see ahead of you, which you need to fix, but what I think what needs work is the effects - It's hard to tell when you get hit by spikes since the player doesn't react to them, there's no screen shaking, or particles coming out of the player.
I think some music and sound effects would help a lot too! They'd make the game a lot more interesting to play.