The idea is nice, but the technical execution, especially the balancing is lacking. Artifacts spawn in spaces where you can't get to them, and the amount of deliveries available vs the amount of artifacts needed doesn't work out, because more artifacts make you slower, while the enemies are already quite fast. A bit of slowing down enemies, while adding more deliveries available, would help the game.
I wanna end on some nice words though. The sound and the graphics are great, and the resulting atmosphere.