I'll cut to the chase on this one. Whilst the game has a really strong style, good music, and a great feeling mechanic for loosing the enemies, it doesn't feel like it was tested enough (by other players at least). Most of the game feels very bland and barren and there's not enough to prompt the player to actually play.
The big issue for me is the lack of anything to really do. Kill enemies, get score, sure, but that largely involves cruising through space for a while, maybe dodging some obstacles, before finally coming across an enemy. But by the time I've shaken off the pursuing ships or even just turned around to get a second shot in its already gone, and so the voyage begins again. Perhaps having arrows show up on screen to pinpoint the directions of nearby enemies would help give the game a better flow, rather than the random "hope to find gameplay" model that exists. I get that this model can work in a sandbox game for example, but in a faster paced arcade shooter it just feels null.
Even if I do kill enemies it just seems to be for a powerup or score. The powerups didn't seem to significant but there was enough to notice a difference. Score on the other hand is quite an outdated concept and it's easy to see why. I never felt as though I was accomplishing anything beyond slowly raising a number. Score milestones would probably have helped, or some means to actually progress through content, or missions, anything really to work towards. Having the score increase be more evident would help as well. As fun as it was to shake space ships, I decided to see how far I could get w/o really playing and just cruising, and I survived without barley any trouble, I just got bored after a while. I did notice afterwards that I could get quicker score by killing the tougher enemies but I hadn't noticed before hand. Perhaps if getting score boosts was more evident, say through numbers popping up, then there would be more appeal. Having to check "did my score go up" whilst playing is always slightly annoying.
You mentioned rougelike elements in the brief description which caught my attention but I'm not sure what you're referring to. This isn't so much procedural generation as it is randomly scattering objects, which works I guess but is a little misleading. Permadeath would imply I lose all my progress on death but as I said before I'm not really making any progress.
Couple of extra notes:
Rocks only being tiny or massive seems odd.
Items and enemy bullets are both white, I never plowed into bullets but I always had to make sure whats what which lessens the accomplishment somewhat.
I liked the shadows that hand off objects. Even though it doesn't make logical sense it works well.
Some indication of being able to shoot again/weapon cooldown would be very helpful given the slow recharge rate.
I like the text that pops up (long shot, ect).
Not telling the player the pause button is annoying, because I have to go around pressing each button it could be before I can pause, likely dying in the process.
A lot of the time enemies seem to just get themselves killed, at which point I feel kind of pointless.
The ship seems to randomly jitter (as does the hp bar periodically). Shake is good for feel but when used seemingly randomly/without and event prompting it, it can feel very sickening and/or disorientating. Hard to say if it's the game for certain but I felt a little sick afterwards.
Sorry if this review was a bit too harsh. I should clarify that the game is certainly cool and has a nice idea with the losing the enemies by plowing them into objects, but it quickly lost its appeal with nothing to really do besides wander, no feeling of want for anything and losing the enemies by crashing them into rocks neither gives me anything nor does it really help when they basically just pile up and get themselves killed if I go in a straight line for long enough.