Nice work on the graphics and the sound. I thought it was a good effort as an fps game but I do have some concerns:
- I felt that the enemies didn't present much of a threat. They basically died in one hit and the player's machine gun as a really high rate of fire and 100% accuracy
- The gun sound did not fire if the bullet did not hit a surface. Firing the gun in the air caused the gun to emit no sounds.
- The enemies and pickups were spaced too far apart. I was basically sprinting the entire time
- Sometimes jumping would not work. I have a feeling that the player can only jump if they are touching the ground and I think some surfaces in this game that look like the ground are not coded as the ground.
Aside from those points I think you did a good job!