I haven't beaten this game yet but I intend to go back and give it another shot! XD
I really like the controls and felt that as I played more I was getting better with them, and as a result was able to get through things much quicker than at first which gave the game a nice speedrunning element. I really like the graphics as well, I'm a pretty big Geometry Wars fan and they reminded me quite a lot of that game :D The audio fits in really well and I like the difficulty.
It took me a little while to realise that I had to essentially scan the walls to find the secret rooms, but once I realised I didn't have any other issues.
Great job! :)