Wow! Thanks for the feeback.
You are 100% right about the lack of sound effects. At the last minute I added some "bleeps" and "bloops" but at the laster minute I took them out because they were to goofy and ruined the "feel." If I knew more about sound design I could have made some better sounds, but the ones I made just weren't good enough.
Thank you very much for you kind words. "immersive" was exactly what I was going for!