The whole thing was very psychedelic. It reminded me of a famous episode of The Simpsons, where Homer ate some really strong chilli that gave him hallucinations.
Length and structure were just right. You had a nice number of barriers to prevent progress and every time you got past one of those barriers, it was a real thrill to see the graphics for the newly discovered location.
The puzzles were somewhat old school. Wander around, find objects, then work out what to do with them. It was pretty much one object per puzzle with not much depth. The connection between the object and the puzzle wasn't always obvious or intuitive. There's nothing necessarily wrong with that, but when you have to resort to trial and error, it sort of takes the pleasure away. There were a few exceptions. For example, the strange mechanism was quite good, as there were multiple elements to the final solution of the puzzle and it revealed something quite unexpected.
I found the end game a bit confusing. I didn't really understand what the animals were telling me. That may have been intentional. I need to replay it to try giving different things to different animals. (I think I know which animal will react to which "treasure".) I was expecting to have to give something to each of the animals, but when I went back to try, most of them had disappeared after talking to them.
Apart from the brute force slog in the middle of the game, I really enjoyed it and hope you write some more. Technically, it was very well written. I would not have guessed that it's your first Adventuron game.