The best-selling games of February 1-7 according to Steam, the online retail arm of videogame company Valve, include a four-year-old hack-and-slash adventure game and three games that weren't yet released.

One new entry is crammed into a chart full of big titles, as 2006's action role-playing game Titan Quest finds itself in amongst the blockbuster sequels of 2010 such as Battlefield: Bad Company 2, Mass Effect 2, BioShock 2 and Modern Warfare 2.

A deep discount midweek meant that Titan Quest was propelled into the Steam top ten of Sunday, February 7. Usually retailing for $19.99 / €19.99, the price of the Gold bundle (the original game plus a later expansion) was cut to a mere $4.99. The recent successes of PC role-playing games Dragon Age: Origins and Torchlight meant that promoting Titan Quest was a shrewd move by the Steam store.

Three games in the chart weren't yet on release at the time of its compilation. Battlefield: Bad Company 2 and Aliens vs Predator are present by virtue of pre-orders alone. That said, those who put money down for Bad Company 2 in advance of its March 3 release gain access to the online multiplayer beta (a pre-release version).

Aliens vs Predator has a multiplayer demo already available via the Steam network and the digital distribution company has thrown in another SEGA-published game for free, Universe at War.

BioShock 2 is released on Feburary 9 and, like Aliens vs Predator, has an older game included in the bundle. In BioShock 2's case this is almost essential, considering the physical goodies that come with other versions of the game. The difference here is that the pre-order bonus was a copy of the first BioShock game, one which scooped up award after award during 2007.

Top 10 best-selling games on the Steam network, February 1-7
1) Battlefield: Bad Company 2 Limited Edition
2) Global Agenda
3) BioShock 2
4) Mass Effect 2
5) Call of Duty: Modern Warfare 2
6) Aliens vs Predator
7) Mass Effect 2 Digital Deluxe Edition
8) Titan Quest Gold
9) Left 4 Dead 2
10) Star Trek Online Digital Deluxe Edition
Source: Steam Network