I really liked the voiceover, and the way you casually slipped "tiny worlds" into there haha.
The mechanics are quite satisfying. The little screen shake and feel of blowing the asteroids up is great!
My only critique would be to include some meaningful progression between planets, like better blasters, maybe a temporary invincibility + speed boost, and perhaps have random asteroids careen around at great speeds the farther you get.
But in any case, very nicely done!