Nice idea, but far too easy and short.
Meteors could be bigger and take more than one shot, that would increase the difficulty. You could also add extra levels with a variety of enemies perhaps ones that come out of mines etc. You could maybe make exploring the mines more than just rolling over them - destroy basic structure or be stationary on it for a certain amount of time.
The graphics could be improved on. The wheels on the robot look like they are on their side which is a little weird.
Diagonal movement is a must!
Keep up the work and you will have a good game.