I am indeed going to add continuous rotation in the future and the flickering I didn't encounter during playtesting the standalone quest 2 version, but it was added later and was not meant to be a version of the game(though I may check to see what is the issue). I do admit that shooting and explosions sound like toys but like you said: it fits the style of the game :)
Also, about the engine, Unreal doesn't provide AAA out of the box which is a problem I encountered last VrJam(wanted realistic graphics) : it's the reason this year I went for this simple yet effective style that anyone can use. Thanks for the feedback :