Thanks, Momo! Means a lot to get feedback like this.
Adding one checkpoint in between ones after the first shouldn't take too much time. I'll do that now, in hopes others don't give up too early.

I think itch.io was down for hours today.

Update: Added 2 more checkpoints, update privately published for both Android and PC. I can't publish them publicly as I am still only of 'New User' rank right now.