Using single floors (mostly) and right angles only in the map design Project Warlock invokes Wolfenstein as its core base of influence rather than Doom/Duke/Quake etc. and in doing so, creates a game that is delightfully simple and extremely compulsive. Each chapter is split into four groups of levels and then a boss and you have to clear these with a limited amount of lives - no quicksaves! - to progress. Experience points from kills and finding secrets let you level up your magic abilities and weapons, eventually gaining some seriously OTT firepower, is a nice loop that keeps things interesting for the duration. Very little fat on this one, which although means few unique ideas it is mostly killer from start to finish.