We're glad you liked our game. It's always nice to hear that someone genuinely enjoyed the experience of playing the game apart from the things that need to improve.
You mentioned a plethora of great idea suggestions. Especially the water bottle mechanic is a really smart one and could be utilized in lots of interesting level designs I think . Some kind of character customization / multiple playable characters also sounds like it would be a fun addition.
Thanks for the words of encouragement! We will definitely try to come back to the project later if we manage to find some time.