Excellent! *spoilers*
I figured out that they might be humans after the "they solve like you" which I considered to be "think like you" and the axe was just confirmation lol. I thought there might be a hail mary when you'd have the option to "let them in" and if you did you would have saved yourself kinda like an good end type thing. The sound was excellent especially the subtle police sirens during a decoding sequence and I really love the little hints and it makes me think that our "helper" was some alien or something because they said that "they look like us" and no human says that multiple humans "look like us" gang.