This is one of the best things I've heard from the piano. This'll be stuck in my head for a while

It's catchy, but it could be better.

The piano sample you used seems a little odd. It sounds like it cuts off, and it's a little too loud. The piano melody is the same note repeated throughout the entire song. You could've put some chords in the song with the piano.

The drumbeat is probably the best part. I don't have much to say about that.

Maybe this isn't a big deal since you're new, but this is such a simple song. Is it supposed to sound that way?

A little advice if you ever plan on making another song with a piano: don't use one sample if you aren't going to use the same note scale the whole time. Add a track for high notes and one for low notes, using different samples of course. I'm not sure how many piano samples your software has, but if that's the only included one, you should probably download a set of piano samples off the internet that may sound better.

One of your best! This song has been stuck in my head for 5 months, and I don't see anything wrong with that.

Here's what I imagine when listening to this song (I'm sure this was intentional):
For the first 10 seconds i see myself leaving the ground, approaching the sky (on a plane of course).
From 0:11 - 2:16, I imagine myself flying through the clouds.
The part with only the strings and piano makes me picture myself flying through outer space.
The rest of the song when I am back in the earth's atmosphere.

This song is very catchy and I like the idea of the song bringing an idea of astronomy.