You have an interesting story idea, and the gunshot as a platforming mechanic is kind of cool, but oh my God this is nearly unplayable. Unless the idea was to fit the "don't trust anyone" theme by making me not able to trust my own keyboard inputs, this is inexcusable. Every action from walking to climbing up the wall locks up randomly and I can't understand why; the double jump has only vertical momentum which doesn't fit with a lot of the platforming; the pistol has a three-shot limit in the air that doesn't reset until you touch the ground, which is fine, but you never state that in-game; and the grenades are impossible to work with.
I'm sure there's a good game in here somewhere, but you need to make sure that the player movement actually works before I'm giving this another chance.