All the sound effects were implemented late into the night before the game jam looool. We tried our best to get all the sounds and music in but were crunching quite hard. As for the arena weapon. You actually get one of the two weapon every time you go through a level. So you might get a shotgun or a pistol.
I’m glad you enjoyed the oxygen mechanics! We thought it was something that would make our game really stand out. We had a lot more ideas for worldbuilding through it that didn’t make it into the game but are still very proud of it.