Great short and to the point introduction of the story, preparing for the comical elements that will follow (as if the name was not a give-away :D )
I especially appreciated the starting area being a corridor I had to get familiar with the movement before I could move. While I do understand people's slight frustration with the movement system, after playing through it all I have to say, I now view it as an advantage for your translation between species communication: as a human I can move the human arm with great precision, yet cannot easily walk a mile on a mouse's shoes. That said, I agree with comments about the speed, perhaps having an acceleration added, that picks up speed would allow greater movement through the long corridors. Needless to say, I tried moving with the gun's recoil (beautifully animated and coded by the way, with SFX for shots, and reloading etc.) to some success.
PS: Big face statue is the best.