Thanks so much for playing!
Yes I'm as disappointed as you are that I wasn't able to get to the second level. I had the enemies and the textures and mechanics ready to go, but just piecing it together would've required another half day at least. Which sucks because it would've been a more Doom/Quake style level, to showcase the duality between Kyle and Billy.
In any case I do plan to finish the game and add a couple more levels, I've come too far not to complete it!