so, the jump with spacebar seems slightly delayed which does feel a little odd and takes a minute to get used to. You have platforms on the second level... maybe a good idea to have a few unstable and collapse after say 3 seconds? it would force forward movement and stop people from being able to carefully plan and instead create a sense of danger and hurry. the door which you get to to end the level, maybe have the character actually "go through" and then auto load the next level. Im sorry if this looks like a list, but it does have good bones :D