It took me a while to beat it, and it was quite the journey. I love the concept of getting to the top of this large turtle creature thing, and the freedom to view the creature in its full glory at any time is a fun touch, and I also enjoy the micro-scenery changing from the creature's body, to the shell hills, and finally the white tower thing.
Also it took me a while to figure out how the dashing works, and it feels a bit, ahem, unstable to use in that once you hold it and then jump, it is really hard to control your momentum even when you let go of it. The checkpoint system could be improved by making it more lenient (like maybe giving you the checkpoint as soon as you land on the platform), since on a few occasions I would land on the platform but fall off due to having too much momentum from the dash.
Lovely game, great concept, good job!