We had a bunch of ideas for the one shot element of the game, but limiting the players shooting wouldn’t have worked with the gameplay, even if it was just for some power up like an rpg or something.
We decided it would be best to have a narrative/gameplay element where you need to play through the campaign in a certain way, completing missable objectives in each mission to unlock the good ending i.e. you have one shot to complete the final objective, if you mess up an objective you’re locked out of the good ending/final objective.
Since this was a Ludum Dare game we made every single asset from scratch and ran out of time to implement this system (especially trying to get a working web build) so we decided to just make it so that the final boss has a one shot sequence you need to pull off to win