Fun and surprisingly addictive! I relied heavily on the strategy of ducking in and out of cover. There's a bunch of hitbox fun to be had -- if I felt lucky, I'd let the rotating squares' bullets brush by me, leaving me free to return fire. The boss made no sense until I ventured further in and observed it closer. After that, it was easier (and far more fun) to lead and beat the boss than it was to dodge the 6x bullet-spray machines.
Clever way for packing a maze together -- I had to backtrack many times and choose my battles. I'll re-test my reflexes and explore the rest of the medals later. Vey nice game!