O.R.O.S.I.

 
Background story:
O.R.O.S.I. Inc. has been assigned with a special task to develop a lethal weapon you cannot shoot. Sounds impossible? Not for scientists from O.R.O.S.I! Still not convinced? Then enter the training simulator they developed specifically for you and experience it yourself!
Controls:

W, A, S, D – move

Shift – sprint

LMB – “Shoot”

RMB – Change gun screens between showing the player’s health and the number of remaining enemies.