Part of that open-ended gameplay comes via the graphics and physics engine of the game. While Ion Storm admits to using Epic’s Unreal engine for the beginning of development, it’s clear that the final product has greatly altered the engine for Invisible War. From real time shadows that you can hide in to multiple paths and choices to move in the levels to highly detailed character models, Deus Ex is one of the best looking games we have played this year. The world is also highly interactive, whether its activating the news terminals for updates to chatting with both NPCs and main characters you need to chat with and the physics engine that makes anything not tied down movable and usable. What a shame that Ion Storm has elected not to released an SDK for this game; we think there is a lot of potential for some solid mod work for Invisible War.