The game was really good! Managed to complete it on the first try, nice rest during my work hours :) I'm guessing you did change the difficulty? I found myself finding too many HP packs from asteroids which was the reason why I could finish it during my first try. I'm also guessing that the closer you are to the distress signal guy, the more HP packs you get? It did feel like I got more HP packs the further I was from earth.
I also think that the enemy ships did little damage, but considering how close they were to me and how they stick to you, it's reasonable.
Using asteroids as cover while fighting the enemy ships then breaking the asteroids myself when I had less HP was the way to go. (Edit: And it felt really good as well haha!)
I initially thought I could deal with more than 1 enemy ship using the missile (RMB) because it was kind of an AoE effect, but I noticed that I could only take down 1 ship at a time and that it was a 1-hit missile.
The RMB and Space commands were a little confusing at first. I initially thought that the space button was some sort of dash that I could use to dodge shots while in the middle of a fight, but it is more of a booster to reach your goal faster, and can only be used when the bar is full. Still, once you figure things out, everything works smoothly!
It was a great experience!