Ok, I got all the medals from this game in under 45 minutes, so it isn't impossible. You're just going to need to rely on the restart button a lot. The game will sometimes spawn a star near a enemy cloud early on or sometimes just straight up kills you immediately by having all the clouds attack you at once before you could even do anything.
Other than restarting when you need to, the best thing to do is to try to snowball by getting a few extra clouds, spend a star to get the temporary boost, and then just spam space and click.
Spending stars to upgrade clouds isn't worth it in this game.