This is super awesome, not just as a proof of concept but actually very playable! I'm running it on stock C64 hardware with SD2IEC and a 1351 mouse. I was gonna play the whole episode last night but i failed on map 3 (toxin refinery), fell into the "moat" and couldn't get out. :)
Two things: RMB does not work for opening doors or operating switches, you have to press K on the keyboard which is pretty inconvenient when you're playing with WASD/mouse. (RMB selects "no weapon", same as pressing 1 on the keyboard.) Second: the mouse is VERY sensitive, to the point where 50% would be more than enough. Would it be very tricky to make a test version where the mouse sensitivity is 50% of what it is now?