Just did a simple run, but for the moment seems really a nice game, great work. Will play more the upper levels to see how it changes.
Finally finished the game, nice change with the last level, luckily I bough some extra ship and I managed to survive some difficult steering thanks to the boost speed. I enjoined playing it, as a fist game I would say a real success. As suggestion I would add some more weapon, like something that fires also diagonally, maybe a temporary shield that gives indestructibility for some seconds. The Level 4 and 7 where you can only evade are difficult and you don't have any reward at the end, maybe throw a couple of diamonds here and there.. or at the end two mystery "?" treasure that can give you money or weapons.
Hey you did it, congrats !!
Definitely a shield bonus is a good idea and I'll add it in next version !
I also like your suggestion of adding some rewards on levels 4 and 7 ! (and maybe some "gravity blasts" and shields here and there)
But I think the rewards must be gold ore rather than diamonds otherwise I fear to unballance the shop.
Talking about ballance, I have the feeling that after some levels the shop tends to loose it's interest because you don't have anything else to buy did you have that feeling too ? I was considering making the golden skin very expensive (like being an hard achievement) and activating a little percentage of the "bonuses attractor magnet" permanently (except in the cave level) when you buy it...