This game has a wonderful world and personality to it. I would love to see so much more from these aliens and their fish-out-of-water assessments of Earth. The platforming was solid, and the writing was great. One thing I would recommend is making the double jump animation feel a bit more weighty- like the character is propelling himself upward more on that second jump. Maybe you could even get a bit of in-universe feel to it if the character was wearing a booster pack or anti-grav boots, and there was a little boost of smoke that came out when they did the double jump. I hope you continue with this project though, it would be so much fun to see more levels where they interact further with the human world. And possibly even at some point if they met some humans!
I actually recorded my playthrough. If you want to see my impressions as I played, you can see it below (timestamp for your game in the description). Hope that can be useful!