Ofcourse you can't make this on your own, noone can and you shouldn't expect to. You need to focus on making either small demos or getting involved in a project with a small team to make something a bit more substantial. It's unlikely you'll be involved in anything like this until you get into the industry.

Now that the price dropped by 25% on steam I bought it. I really liked the demo. There are just too few 3D platformers on PC. Which is a shame, I absolutely love games like Ratchet & Clank, Jak & Daxter, Crash Bandicoot etc. Comparable titles are rare on PC. Titles I remember: Pandemonium, Gex 3D (yes, I'm THAT old), the newer Prince Of Persia titles, Duke Nukem Manhatten Project, Psychonauts.

Super Mario meets Spiderman meets Barbarian, with far too strong bloom effects.

But... somehow it looks cool nevertheless :)