In case you're interested in reading up about Irrational Games' history, EDGE has you served with a brief article on it with comments from employees at the company. Here's a snippet:
Navigating the constraints of tight budgets and outdated engines, the burgeoning team at Irrational infused System Shock 2 with (a mood and a vibe), as Levine succinctly puts it. This was something that would become apparent in an early prototype that Levine recalls as being one of his fondest memories of the project.
(It was basically a demonstration of the shooting and RPG stuff, and it really was cool,) he explains, an enthusiastic grin spreading across his face. (I remember playing it and it was not functional in any way, shape or form it barely held together. We had no AI. We had things that pretended to be AI. We had lots of things that pretended to be things, but there was no real anything. But we really tried to tell a story in this space with the limited tools we had and I remember finishing it and thinking, '˜Wow, we created something that has an emotional feel to it.' It was powerful to me as a setting, sort of a vision of my future as a game developer encapsulated in this demo.)
Fortunately for the studio, System Shock 2's roleplaying leanings were a hit with critics; 90 per cent or greater scores abounded (as well as eight out of ten in E77). (We were as stunned as anybody else as to it getting the reaction it did from the press,) admits Levine. (I think we expected the critical reaction to be on par with the commercial reaction, which was tepid.)
And therein lay a hard truth for Irrational. Although System Shock 2 spawned a dedicated fanbase that thrives even now (mods are still being cobbled together that improve the game's graphical fidelity and overall performance), the game failed to ignite the sales chart, crossing the 50,000 copies sold mark around six months after release.
It would be eight years before the studio produced a title that was truly commercially successful, despite working on well-liked and critically praised games such as SWAT 4 and Freedom Force Vs The 3rd Reich in that period. Yet despite the sudden influx of capital and obvious physical growth of the company that it brought, the success of BioShock changed Irrational's work ethic surprisingly little.