The game idea is definitely very unique and the added complexity by changing character states and abilities is very nice. The addition of the timer definitely makes a lot of sense and it is definitely fun for the player to try and achieve the best times across the levels by most efficiently trying to use the different abilities. I think adding some more environment backgrounds or textures would be nice although I do recognize the simplistic/old theme you are going for. One critique is that I think working with a camera a little more or adding a mini-map would definitely be good for the player experience.