The level of difficulty is perfect, the art is cute. I like the checkpoints and the fact that you can easily find a place to rest is great. My biggest suggestion would be to have some delay between dying and going to the checkpoint. It kind of jerks you away and it's a bit jolting. Otherwise love it!
I also think it could be nice to have a health bar instead of immediately jumping back to the checkpoint, at least for the gears or something. I could see wanting the spikes to immediately take you back, but the gears move a bit funkily so sometimes it feels like you didn't hit it but you still have to restart the level. I do think the checkpoints are in good places though.