Believe I made it quite far into the second level before I also got locked out. I was very careful to ensure I never used the special attack without an enemy infront of me, and I avoided the bugged door at the beginning of the second level.
However much further into that level (I had probably got through 3-4 doors or so (not quite sure as I wasn't counting) when I was able to use a key to open a door that took me off the map. I'm not sure if this is the same bug as point 2 in your comment. however I couldn't progress any further, I'm assuming because I no longer had a key.
I was quite determined to finish to at least give you a decent appraisal but I then bugged into a wall and got stuck. I tried to reload but the load game button didn't do anything for me.
Really sorry I can't give you more regarding the complete game, but I will try and give you some constructive feedback anyway from what I saw.
I think the filesize is probably quite a big problem. Unreal definitely makes big files, but this is probably just too big for alot of people to want to download for a short game. Not sure whether you could have scaled the textures back or used lower LoDs.
The ideas behind the combat is a great idea, I like the thought having to charge a meter to heal myself instead of just looting stuff. The actual combat itself rewarded spam clicking so could use some tuning.
Overall it was really smooth sailing and fun for me until I hit the bugs, these things happen sadly, but I do hope you have another go for the next jam.