Day 3:
Did loads of stuff today which is good because I have work all next week. I gave the cat a jetpack for a bit, but it isn't as fun as moving the arms so it might be temporary. I made some spikes which hurt the cat, though can't decide whether it should trigger the level restarting, not sure if I want it to be that challenging. Also made some rainbow rain for effect. Not sure what that effect is, but it's certainly there.
Challenge now I think is to decide on a main mechanic and improve that, make sure it is fun, then add in extras. Also make it feel like you are progressing through the game, either by notching up difficulty, adding more elements, or driving forward some kind of visual narrative. It helps that you are always heading upwards I think, as that gives the game natural momentum, and a feeling of moving towards something.