It's a start, but I feel I'm going to like it afterwards!
If I can throw ideas like that :
- Maybe a way to convert his rocks into an upgrade for his ship (weapon, shield,...)
- To have your highscore stored somewhere to try to beat it every time.
- Having events (such as a flaming meteor shower,...) or a leveling system to add random difficulty as you progress through the destroyed rocks and the improved ship,...
If you need a French translation for later, don't hesitate!