The graphics is nice, I like how there is a character pop out when get hit.
The gamplay is simple but the music is nice, I also like how you use different music in different dimension.
The damage act as currency is a cool idea but the it makes the dps don't make too much sense when it don't deal any damage to the enemies and just "damage" on the top.
And you can basically skip the middle ship since it is very easy to get damage when the dps price don't change.
But still, nice game!