Thanks for response! I checked to be sure and it seems I made silly mistake with colors 😅 I will leave it in original comment, but to clarify - I gave up on part with blue key not purple. Well, it gives me chance to elaborate.
Blue key is in my opinion hard to access (I'm looking at you, pirate rhino and sloping wall!), so struggling to collect it after every mistake (especially with such long and painful path to door) makes this part feel quite exhausting. I think it could be more bearable if checkpoint saved key, or maybe setting one checkpoint closer to spawn point of this key?
On the other hand real purple key (if I'm not confusing them again 😅) was on the path to bookshelf. Getting it to door was challenging but fun (I have praised beam already)! The key (:P) diffrence in my opinion was very easy return to purple key after small mess up (just falling down in good direction), so I could start another try quickly. It can be just me, but struggling to get key somewhere felt more entertaining, than struggling to collect a key 😅
Sorry for any confusion! I'll be happy to check out future updates (so glad to hear that current save file will be useful) and give more feedback. Best wishes!