It'll come as a shock to no-one: Rockstar North has decimated the competition, climbing directly to the number one spot on our monthly chart.
The ranking, provided exclusively to Develop by Chart-Track, is based on revenues generated at UK retail, the third largest market in the world.
Of course, Nintendo still manages to put up quite a fight, sulking and licking its wounds in second place despite extremely brisk sales of Wii Fit. Of course, there's been a much-publicised stock shortage facing many UK retailers, but it's unlikely that even limitless units would have helped yoga and aerobics seem more appealing than the intoxicating cocktail of sex, drugs and hit'n'runs that GTA so deftly provides.
Sega, Konami and Infinity Ward all manage to continue their hold over the top positions of the chart, but the real mover this month is Harmonix and its peripheral-heavy rythmn action title Rock Band, kick(pedal)ing the musician-heavy studio 96 places up to number 11. Of course, having an RRP of £180 - comfortably four times the price of most of its contemporaries - would have certainly helped somewhat.
Three new studios manage to make an entry this month too, despite the GTA juggernaut, first of which is Free Radical Design shooting into 12th place thanks to the Haze publicity machine despite only a short time on the shelves during the survey period (April 27th - May 24th). Normally we'd predict a rise in next month's position once the title's had a little more time on store shelves, but given the game's almost uniform critical rejection we wouldn't bet our mothers on any dramatic change.
Also new this month is Funcom, whose much-anticipated (and oft-delayed) MMO Age of Conan: Hyborian Adventures had a super successful launch despite again only being released towards the end of May. Expect a long tail on this as expansions, bundles and budget re-releases seek to keep those all-important subscriptions active.
Final new entry is Secret Level, the Sega-owned studio entrusted with the Iron Man franchise - or at least the Xbox 360 and PS3 versions, anyway. Interesting to note is that A2M, responsible for the PS2, PSP, Wii, PC and DS versions of Iron Man, have placed six places higher - admittedly more platforms, yes, but further proof that movie properties work best on the more mass-market machines.
For the full developer chart, take a look here.