This is such a cute concept! I'd love to see this fleshed out and expanding on because I love the idea of a little alien creature roaming and exploring earth in a platformer style. It felt like you could explore the world with multiple paths, and I had fun going about wherever I wanted. The pixel art is really neat, I love the square yet organic feel the environment has. The animations are also really cute.
I would say that my issue about this game is the controls and physics. It felt frustrating trying to jump from one platform to the next. The alien would benefit from having a lighter weight, as it was hard to jump between platforms. I couldn't make it from the cave to the higher level because of some of the physics. Tweaking the slopes so that it doesn't affect the jumps and fixing the bug that makes jumps next to tall platforms weaker would help.
I do want to see more from this game though and it looks like you've accomplished a lot for the final!