Thank you so much for the kind words and thorough feedback. Yeah some parts of the game are rather jank. The game was originally conceived as a dead space fangame where you just command things as the marker but then I found that gameplay to be fairly tedious and slow (also the way the infector didn't mesh well with the eventual swam vibe).
So I then came up with the "anoint a group to be a hero group" mechanic.
You're very right about it being too long though. I did tweezer the first 4 levels repeatedly to be good tutorials and once I adopted the theme of Dante's Inferno I felt obligated to create the rest of the rings of hell. I think if I could go back and do it again I'd just have 2 types of zombies and just have the game be a 3 level affair with the 2nd and 3rd level being procedurally generated.