Gave this a try and I must say, really enjoyed the movement in this, that is, if it worked. Was completely clueless on how the game worked for several minutes until i figured the little text saying danger/safe indicated if your shotgun gives you a knocback boost or not, which as far as I can tell switches completely on random. My guess is this mechanic was added to satisfy the requirement, but honestly it just ruined the fun, better limiting mechanic would've been the magazine size where reloading would force you to stay still for some time and the requirement could've been satisfied with some narrative thing or something.
All in all after figuring how the mechanic actually worked the game was fun to control, however with extremely sprawling levels and no indication as to where the goal is I was still left confused. With some tweaks and proper level design (and now without the game jam limitations) I can see it being a fun and fluid platformer.