Great game! I like it, but here are some suggestions that could make your game less punishing, unless I'm just being a baby about it.
1. Improve Purple Hand jumps (They are extremely punishing in the chase scene when you don't do it properly.)
2. Increase the Flare Hand stun time by about some extra seconds, maybe 5 seconds total?
3. Slow down Pianosaurus on the chase scene, I get it, it's supposed to be a chase scene, but one wrong move and its game over, really. You have to do everything picture-perfect in the chase scene. Just slow him down a little so the Player would get some breathing space to recover quickly, but make him fast enough to punish the Player for being so damn slow.
4. Pianosaurus sometimes notices me even when I'm crouching, when I didn't walk, run or even use my Grabpack, fix that please unless I'm doing it completely wrong.
5. Make the Flashlight a bit brighter so players would be able to see within the cave much better, rather than seeing pitch-black darkness. I get it, it's supposed to be a dark cave, but just make the flashlight bearable to use within the cave system, please.