Tough as nails, visually coherent, and jam packed with action.
Aside from the occasional floating gun (Totally not a bug; it's alien telekinesis!), this is a great deal of punchy high-octane fun in a small package.
I recommend a volume slider for the music and sound effects, as the latter was disproportionately loud, and you can never be quite so sure of the sound settings of the player. Otherwise, great work!