Thanks for trying out our game!
The checkpoint feature was added in a rush without any research so I wasn't able to try making multiple checkpoint feature, but I feel like I now have an idea how I want to make it.
For the grounding issues, I did experience it as well but I'm not sure how to fix it yet so I had to submit it while knowing that the issue is present. Maybe I'm mixing a lot of detection that's why it's happening but I'll try to learn more from this.
Again, thank you for trying it out! We really appreciate it!