I liked the whole minimalistic mechanics of movement and combat, more similar to the old Dungeon Crawlers but with a shooter aspect to it.
My main issue here is related to shooting, since the time you press the input and the actual time the bullets spawns is too much to telegraph easily. And the ammunition should be replenished each mission, or at least there should be more ways to replenish it outside the randomized rewards.
Overall is a nice and distinct entry, good work!