I 100%'d it, no problem. Even got an achievement and found the secret ending; really like the twist at the end where you find out the main character was you the whole time.
But seriously, the variation in the tracks is fantastic, you really covered your bases with this. This felt like a classic platform adventure on the N64 with all the different worlds you could visit. Really reminds me of Grant Kirkhope, honestly. Great job.
Also, side note, I've noticed you give very insightful, and thoughtful comments, great job on that too.