I've been playing the demo, and after seen your profile, it looks like it's the first game you ever publish. Congratulations on that! just the fact that you finished it is something you should be proud of ヾ(•ω•`)o The main idea of Triple Jump is interesting, and you have some good level design. However, there is room for improvement.

Sometimes the different scenes and sprites look a bit off, like they belong to a different games every time. You should be more consistent between them, set a style and stick to it! otherwise the player can get a bit confused. I see the story explains you are playing some kind of simulation, then you should have a consistent "simulation" style and a consistent "inside the simulation" style.

Also the game could have a bit more juice. By having, some kind of jump or landing particles, smooth transitions between scenes instead of instantly loading them, some sound effects or animations when you die or you win e.t.c.

In terms of polishing it, it would be nice if you could pass between scenes by pressing enter or esc so you don't need to reach for your mouse every time you get to a scene that requieres you to press the ok or back button to continue.

When it comes to content, 5 worlds and 80 levels is a great number for a beginner! but don't focus so much about making huge games, think more about making small and well polished experiences! At least those are my thoughts, I wish you luck with your future games ^^