Another aspect that gives this engine its punch is its sense of scale. Huge bosses rise out of the lava or muck to fight you and they dwarf even the massive buildings and pyramids. Lens flares, explosions and substantial collateral damage to walls and flooring are also present. You can't blow open doors or walls, and the gameplay is typically a simple key/switch/lever hunt but that's OK because this is a pure action game and puzzles just get in the way. The engine's weaknesses are there in service to the gameplay here. Best of all, the full engine tools are available with the game. It shouldn't be long before we see amateur maps available for download.
The audio is uneven, featuring brilliant samples like the grunt of a Werebull and the scream of the kamikaze guys and also the incredibly lame one-liners Sam himself spouts. I really wish they'd kept our hero silent like in the tech demo but they didn't. He's like a moronic Duke Nukem. The music is sheer perfection for this kind of game. A mix of tribal drums and other odd instruments, it invigorates the action and makes you wonder why most shooters bother with techno instead.
The weaponry at Sam's disposal is your typical assortment of pistols (single or double), shotguns, machine guns, a laser gun, rocket launcher and more. All have been balanced fairly well for the action. There's always a trade off between speed and firepower. The monsters are brilliant, not in terms of artificial intelligence, they don't really have any, but they're incredibly aggressive and tenacious. The bestiary features rocket launching headless guards, the aforementioned kamikazes and Werebulls, Gnars (creatures very reminiscent of the pink demons from Doom), harpies, and giant mech creatures. Most of these critters are destined to become classics. Up there in the annals of greatness with Doom's Cacodemons, Duke's Pig Cops, Quake's Fiends, Unreal's Skaarj, and Half-Life's Everything.