There are several Quake related mission packs and conversions available on the local software store shelf (Quantum Axcess' Shrak and WizardWorks' Q!Zone to name a couple), but Activision's Scourge of Armagon is the first to maintain the quality level design of the original while adding some great innovations.
Armagon contains three new episodes and a deathmatch level, with new monsters, weapons, and power-ups. New environments include revolving cement-mixer passages and blood-red waterways, and an abundance of traps, from huge whirling drill-bits and spinning saw blades to hundred-foot lava pits and tumbling rocks. But we don't want to give away all of the surprises. Suffice to say, you shouldn't go taking pot-shots at the crucified guy in the Black Cathedral if you know what's good for you.
Among the new monsters featured are the Centroid, a huge mechanical scorpion with a nasty stinger and two nail guns for claws, and Gremlins, hell-baboons who descend upon you and steal your best weapon, using it against you to the best of their simian abilities. If these little cannibals are outnumbering you, try killing one of them and then see if they'd rather have you for lunch or their freshly carved-up brother.
So what new weapons will you use to splatter these dungeon dwellers in Scourge of Armagon? The first you'll come into contact with is the sporty proximity mine launcher, which fires motion-detecting grenades that will attach themselves to the wall or the ceiling - stand back and watch them blow up in the face of an unsuspecting passerby. Next is the laser cannon, which sends blasts of fused energy ricocheting from walls hither and yon, searing any flesh that enters its path. The final weapon you'll come across, the Mjolnir, comes straight from the workshop of a Valhalla blacksmith. One epic strike at the floor, and this over-sized hammer emits lightning bolts that juice anyone standing close by.
The individual levels are extremely challenging at first: Any time an object of importance is retrieved or activated (such as a key or a switch), you can be sure that you've just unleashed a pack of intimidating monsters who are waiting just around the corner. Five words can describe a few of the more difficult levels: Lots of Vores and Shamblers! If you're lucky enough to grab the Horn of Conjuring (a new power-up), you can actually recruit a monster to be your brother-in-arms, fighting by your side against his erstwhile brethren. There is also an Empathy Shield available that lets attackers "feel your pain" as they lay into you.
Many of the levels are perfect for deathmatch. Edge of Oblivion - presumably set atop some kind of multi-tiered floating space-station - is a great environment for fragging over the network. Be cautioned however: Accidentally tipping off the edge will send you hurtling through the atmosphere, 2001-style. But perhaps the most exciting and heart-accelerating deathmatches occur in the final level (where you meet the half-mechanized Armagon in the single-player game). Perfect in its design, this level consists of only a single room (similar to Quake's House of Chthon), has every weapon, no armor, and practically nowhere to hide. Needless to say, the room begins to look an exploded morgue after only a few minutes of play.
This add-on comes highly recommended for anyone who just can't get enough of the original. With a cool new soundtrack and challenging levels, Scourge of Armagon is more of the same good thing. The only real drawback is the price, which is a bit higher than the other add-ons available - but if you're willing to shell out the cash, you will be sure to find Armagon an excellent addition.