Definitely an extremely well designed game, combining puzzle and platforming elements together really well. I saw the comments saying that the speed is a bit fast, but I think it's more of a problem with the acceleration. A slower (not-instant) acceleration to max speed will help with not speeding into random spikes and make being able to turn and shoot projectiles without slamming into something a lot easier. The max speed is fine in my opinion. Other than that, there is an issue in the final optional challenge where at the very end, last platform, the camera movement trigger is a bit too low and jumping to the very last platform will cause the camera to move while you are still in danger, which is annoying. Also, I felt like I sort of skipped some of the parts for the final optional challenge (went above the moving spikes rather than inside the ground), but had a lot of fun!