This was a bit of an odd duck for me with a lot of ups and downs, making me a bit confused on how to feel about it!
On one hand, many kudos for hiding a game within a game, and done in such a secretive way that many people might not even realize there is a secret in the first place and might just write this game off as a bog-standard collectathon platformer that it appears to be at first glance: takes some balls to pull off a risky move like that! Even though the whole 'player rebels against the creator' angle has already been done many times before, it was still a neat twist and I enjoyed how the gameplay evolves in so many ways and had multiple endings and such as you get deeper.
On the other hand, I came very close to quitting this game two times and it was only through the grace of god that I got lucky enough to make it through. The first time was me boring myself on the initial boring collect coins gameplay loop: as I was just quitting the game, I happened to glance at the description and luckily see the hidden clue, for any other time I would've just quit and thought the game was dull as dishwater. The second time was in the big unfinished RPG world where I was starting to get really annoyed with how big the world was and how easy it was to lose so much progress from a flubbed jump or a dumb trap: I was just about to quit since it felt like I was making no progress, but again, luckily I happened to find the spaceship at the very last moment and then get a cool ending boss fight.
So yeah, it's a bit difficult to judge! While I enjoyed the secrets and subversions, I still found it a bit of a pain to play at times: even looking past the things I mentioned, there are also other silly things like bad feeling platforming physics and the annoying need to redo all the dialogue/cutscenes on a fail. It's like if parallel worlds exist, I think this is the only world where I got lucky enough to actually play and beat the game, whereas every other world I would've quit out of boredom or annoyance and I wouldn't blame them for doing so. I mean, I did get the ideal experience, but does that mean it's good, or that I got lucky, and how should I score it? Ok, now I'm getting silly, but anyway, it's a mixed bag I guess!