Really fun game! Simple but incredibly polished, love it. Feels incredibly similiar to a Vlambeer game, the only feedback I have towards Juiceness is to implement some sort of pitch variation to the gun sounds as they can get very repetitive with time.
Now, seeing that this game really has potential beyond the jam, I'll be noting some game design feedback that you shouldn't consider for the jam version, but maybe for a future update or some spin-off game:
For design choices, I think that continously clicking the mouse button to shoot can be annoying with time, especially as there is no reason to not implement auto-fire in this case.
Also, it would be interesting to see some sort of reload and perhaps another way to get around the level and breaking boxes other than shooting (maybe headbutting?), it gives this feeling of tension and strategies have to be more strategical rather than just shooting everything recklessly.
And what about other weapons? Automatic, semi-automatic, or damn, even grappling hooks? There are hundreds of possibilities, really!
And finally, this type of game fits perfectly with a procedural level generation. Having every run to actually be different makes the player feel a different experience everytime, I can see it applied to this game.
Wonderful job, I suggest you think about this jam game and perhaps make it into a real commercial game! GL!