Demon Genes I is a single map for Doom 3 by Caffeine Freak. Maybe I'm out of practice, but damn this was a tough run, in more ways than one.

Difficulty: 9

One thing's for certain, if nothing else: This map is HARD. Do you remember how in the original games, whenever you played a custom map, you'd always have these points where enemies just kinda started teleporting in, over and over? Yeah, you can expect some of that in this map. At any given time, once you get through the initial areas, something is constantly trying to kill you.

And it's dark. Holy crap, if there was a map that you really wanted to use the infamous Duct Tape mod on, this would be it. Lighting is sporadic, and it seems ambient lighting isn't used in some areas, leaving only the projections from specific fixtures. Not only do you begin to dread what might be down that next corridor, but once it starts attacking you, you're in a spray and pray situation.

Or just use grenades.

Either way, this is probably one of the hardest Doom 3 maps I've gotten my hands on. You can expect to see almost the full Doom 3 enemy roster here. Pinkies, commandos, archviles... The only beast missing seems to be the hell knights and mancubi. But with so much trying to kill you, and all at the same time, consider that a blessing.

Also, you'll wish Doom 3 had an auto run function. Just saying.

Design: 9

The detail on this level is amazing. Everything fits the abandoned Mars base motif, areas are compartmentalized so you have an idea on where to go next, and the facility is sprawling. Seriously, this is an amazing map. Hell, there are even logs you have to pick up to find codes; a rarity in most custom maps I've played.

Though, one minor criticism - Since there is very little in the way of ambient lighting, it's almost as if the darkness itself is obstructing your progress. I don't mind a few dark areas here and there, but outside the light cast by the fixtures, it's pitch black.

Playability: 4

It pains me to say this, but I had to deduct a few points here. Unfortunately, there is a game-breaking bug in the morgue. If you get to the exit door after the lost souls attack you, the map freezes, and you have to close the game via task manager (if you're on a Windows box). Over and over, I was getting this to the point where I thought the map was going to be unbeatable - Not for the difficulty, but just being able to get to the end without crashing. I don't know how I got through that door the last time, but Caffeine Freak, if you're reading this, please look into this bug. I'd love to mark this higher, really, but this is a huge issue that needs to be fixed.

Overall (Not an Average): 6

Really, Demon Genes I is an awesome experience, but that nasty game breaking bug keeps me from giving this a near perfect score. Try it out, but keep your distance from that bug until everything's quiet, and then proceed. As long as you keep that in mind, you should be fine.