A so-called "concept review" is simply a review done in any style other than the straightforward observation/analysis/criticism model. The name itself is an ironic reference to the predilection of terrible '70s prog-rock bands for making "concept albums", which were nearly always about trolls.
Concept reviews were pioneered by the likes of (The Legendary) Duncan MacDonald (all bow) and spread via the influence of Zero and its progeny to most computer games mags of the late 1980s. Who could forget, for example, Sega Zone's multiple-choice questionnaire, the Gamesmaster footy game review In The Style Of... A Reader ("It has good graphics and is good because the sound and gameplay are good"), or Sega Power's Ecco the Dolphin After... The Writer Had Taken Speed, ironically written after the writer had taken speed?
Most computer games mags of the late 1980s, that is, except the Amiga ones. Concept reviews were one of the main defining elements separating AP from its idiot competitors - few had the imagination to attempt such things, and significantly fewer the basic writing skills necessary to pull them off successfully. We can't, off the tops of our heads, remember anyone else ever doing a good one.
Famous example of ones we did that were great include the regressive hypnosis review, the stunt double review, the perceptive Ed review, the Game Zone Tribute review, a review In The Style Of... Have I Got News For You, a sociology exam, the secret decoder ring review and the automatic self-scoring review. However, by far the most popular form was the script.
The wizzle-teated drying-up of Amiga games put paid to the concept review (less than, say, five games in an issue and it was considered bad form to have more than one written In The Style Of...) but, happily, the approach returned for the final issue and, unlike the brutally slain AP staff, lives on in mags such as PC Gamer. And possibly ones not dealing with computer games. Although not, we'll be bound, film mags, despite the potential for some cracking secret irony.