?? I thought all that was showcased would be great as is! Though, as with any game, adding more levels/characters/etc. would make it more fun to play for extended periods of time or over multiple sessions because there would be more to do.
As for, "They will tighten the graphics, game design, and sound design, and it will be interesting," I imagine your comment wasn't meant to come across as such, but this part sounds especially condescending since... well... the game is alreadyinteresting-- you said so yourself! Plus, all three of those aspects you mentioned are quite polished in-game. Like... d'you see those vines?? Dayumn! And don't even get me started on that crunchy ground texture-- mmmm!~
Overall, I'd say this game is one I'd love to come back to play again and again in the future!