One of the core elements to understand about this game is that not every fight is required, a great many of them can be skipped by running through to the next area, typically once you pass a certain point the enemies you've by-passed will be locked out from following mitigating the danger. Often some doors will open after a set wave has been taken out, opening the door to allow access to the next area whilst having new foes join the fray. For instance, on stage 2 (Red Meat), you will arrive in a meat locker where 4 meat packers will attempt to add you to the meat racks, if you take the 4 of them out, the door will open at the far end letting 2 more come in, at this point you can just leave as they run in (often it's a good idea to let them run in and then slip past them).

Another tip is to use the Ice ability as soon as you get it, this takes most enemies down to 3 assorted shots (1st shot, freeze, 2nd shot solidify, 3rd shot frozen and dead like a fish finger). You get this ability in the middle of Red Meat (level 2) after saving Kitty in the managers office. You are able to chain obtaining codes from enemies to keep the meter up, but there will be times you'll want to keep the meter for an encounter you find tricky.

Run! You'll be holding down Left Buffer/L1 a lot as Matt Hazard typically moves like he has forgotten how his legs work.