God my laptop was suffering... buttery smooth 15fps. Miss the days, when Unity games had a startup window for settings. For me most of the difficulty came from the framerate (and I think your movement was also tied to it). Having no air strafing sucked, but I guess that's how the game works.
Felt I had one over the game when I discovered a glitch only to find out that this is the intended way to win (I really like it when this happens).
Personal thing, you set the flag for linux and mac for the game file on itch.io . I would like to remind you that you cannot launch a windows build on neither linux nor mac. It always sucks (at least for me) when I see a game that promises linux support and then it turns out that it's just a windows build.