The protagonist of the game is "Alex D.", a 21-year-old (players can pick both Alex's gender and race). Some of the characters from the original game reprise their roles in this sequel - including Paul Denton, Tracer Tong, and JC Denton (the previous game's protagonist). As before, the action takes place in a number of real-world locations (including Cairo, Seattle, Trier (Germany), and Antarctica).
Like its predecessor, the game features highly nonlinear gameplay, while still retaining a largely linear central plot. Similarly, nanotechnology and conspiracy theories again play a major role in the action.
Unlike the original game, Invisible War was intended from the outset to run on both the PC and a console platform, and its design reflects this: many elements of the game appear to be a compromise between the abilities and environments of both platforms. Although it generally received positive reviews on its release, the game was criticised for its high-end hardware requirements (requiring specific hardware technology to run) and for the relative shortness of the game compared to Deus Ex. In fan communities, debate has raged over what effect various design changes have had on the experience of the game: some fans have voiced concern that the game has been "streamlined" (simplified) too much, others agreeing that the changes were for the best. Nevertheless, Ion Storm has already released a patch for the game to address some major concerns.