The concept is nice! I liked using a power drill as a weapon. The pixel art and music fit well together.
Criticisms:
There were a lot of bugs. The first time I tried the blue portal I shot myself out of the map, and the next time I got myself inside the wall. Sometimes the blue fire of shooting animation stuck with the weapon when I wasn't doing anything with it.
Some clarity would help, too. The instructions say to melee with right click, but that only got me killed, while using left click helped me defeat enemies with ease. The info on using portals in the bottom right corner is very small, took quite a while to even notice it.
I was also expecting to use the drill to dig, but seems like it can only be used as a weapon.