I see, to tell the truth, this project was very much an experiment to test 3D physics and 3D game making in general, as all the Godot Engine development I had done up until that point was in 2D.
Regarding how the first person aspect may conflict with the platforming, I see your point. The inspiration was largely jumping maps from FPS games such as TF2, with an attempt to replicate the rocket jump mechanic, so it never occurred to me. The platforming came second in an attempt to fill in a lack of substance.
Unfortunately, as it stood, I did not feel the enemy AI was sophisticated enough to focus more on the shooting aspect, hence the game leaning more towards the platforming side.
Beyond polishing the project after the Jam with some easier to implement suggested mechanics and balances, it's unlikely I will continue this project further than that at least at this moment, as if it is as fundamentally flawed as you warn it is, it seems it would require a lot of rehashing that i'm not currently prepared for. It is most likely that the code and assets in this project would just be reused in a new one in that event.
Based on your suggestions I'm thinking such changes would in theory involve tamer platforming sections, combined with an improved AI and more mechanics oriented around said AI to put more of a focus on the shooting, or alternatively a third person game with a spot shadow to show the position of the player, and a hub world to encourage exploration. (With regard to the hub world actually, for sure being able to go to and complete any level would be a definite relatively easy improvement, and that may well be implemented.)
As I say, I will probably be adding small features and balancing it, and a second opinion is valued, so I would be really appreciative if you could playtest it in that event, I will let you know if anything happens.
In any case, thank you very much for your critique, I'll try to keep it in mind for any future projects.