I am happy to hear it was fun, because I was mostly aiming for that :-)
After the checkpoint there is no need to use the grappling hook anymore. You just have to keep climbing.
It is still incomplete though, after the rating phase I'll upload an update with complete maps and hopefully turning this more fun.
Including enemies you can shoot with the grappling hook (where the projectile is going to be the characters arm)
cool looking forward to it. I managed to complete it now. Probably died liked 50 times. A death counter would be a nice addition to the game. I can now use the grappling hook to escape the rock without jumping. It feel alot like cat mario in terms of gameplay. When I went to get the 2nd tropy and died because of the spikes I just loled.