I did originally have an idea for reloading mechanics that'd be timed to the beat - with some of them having a quick-reload option! The pistol would take four beats - one for each main action - but if you hit reload again for the second beat, it'd quick-load and be ready by beat 3 instead. A lot of the guns I had this idea in mind, but ended up cutting it instead to go with the older school doom feel. I think if I kept going with this I might take it a step further and reintegrate that, but the main downside was having to animate reloads in stages.
The heavies' shields are actually hitboxes that stop rounds from damaging them! They're the only enemy where aiming matters more, and you have to shoot for the points that aren't being blocked. I wonder if that mechanic might've been a bit too less intuitive to realize - maybe for a future version I'd probably add hit feedback, to make the enemy shield flash when hit, and them react when they take a hit instead.
The boss fight issue is a weird one - thought I'd patched all the geometry - but you can restart the current level from the pause menu just in case. Where did you fall out? I can see about trying to fix that in a future build!
Thank you for playing!