This is very fun for your first game, good job. The levels were fun to learn but not overwhelming, because you introduced your elements on the first level and then just made different patterns with them for the more complicated levels. It was nice to have the UI tell me what they were on the first level.
If you're interested in feedback, here are some things to consider:
- The shadow is important for players to know where they're going to land, but right now it is off-center, likely because of the rotation of your light, maybe? It would be helpful if that is directly below the ufo.
- You may also want to tilt your camera a little more so the player can see the ground more. That way they can see more of the ground as they're falling to a bounce pad, for example. Players tend not to like having to make jumps where they can't see their destination. If you wanted to get very fancy with that, you could give the player some control over the camera, such as being able to rotate it a bit.