I downloaded the Painkiller demo yesterday and gave it a whirl. It's an odd and gory little first person shooter game where you fight against all manner of the undead and collect their souls to gain supernatural power. You can also acquire tarot cards that provide certain bonuses, depending on the card.
The demo gives you access to three levels. The first, is a medeval town (literally) crawling with a host of putrifying ghouls who hurl all manner of detritus at you in your travels through the quaint little burg. The second level is my personal favorite. It takes you into an arabian palace, replete with undead crusaders and scimitar wielding arabian knights. The atmosphere in this level is excellent, complete with middle eastern music. The enemies in this level are so great in quantity that it would make Serious Sam run for cover. In the third, and final level you have access to, you will fight a truly massive giant with an equally massive warhammer that smashes the terrain around you.
The weapons at your disposal are very strange. My favorite is the stake gun that propels giant, sharpened stakes capable of splitting enemies in two, or pinning them against walls. The enemy pain skins are excellent, and there are many different animations displayed depending upon the hit inflicted.
All in all, this is a pretty interesting demo driven by interesting atmosphere, and a different take on the first person shooter. It pleasantly surprised me. Give it a try here: www.painkillergame.com