Combat sometimes gets frantic, but the player is rarely lacking for ammunition or health power-ups. The weapons are interesting to use, and most have secondary firing modes. The handheld phaser's secondary mode, for example, permits changing of the weapon's frequency, which allows it to fire through some shields and force fields. This makes it both a tool and a weapon.
Enemy artificial intelligence (AI) might be one of the weaker points of the game. They're not totally mindless, and will engage you with the different weapons at their disposal. They'll also pursue you once they know where you are, sometimes even smart enough to dodge or wait behind a door, letting you open it so they can get the first shot. They also, however, don't seem cognizant of fallen comrades, and much of the challenge they offer comes from the fact that they take multiple hits to destroy.
The enhancements made to the core Unreal Tournament engine work well. The lip synching technology Collective Studios added does bolster realism, as does the skeletal animation system. The use of Trek staples like the tricorder and communicator are handled intelligently. For example, the tricorder truly is useful, revealing valuable information about objects and targets. The communicator is sensibly designed, and supports wheel mice, so it's easy to engage it, scroll to a correspondent, and select them with a minimum of keyboard access. When characters have something important to disclose, you're cued to it by a flashing symbol on the screen, and noteworthy correspondents are highlighted so you don't waste time on unnecessary dialog.
There is also a sneak mode that lets you move silently. This stealth isn't just there as a feature bullet. It really benefits you in some situations where you might need to creep up on an enemy and then take them quietly in hand-to-hand combat.
The Fallen certainly has some issues that collectively make it imperfect, but individually aren't game breakers. Some of the combat is a bit cheap, since it's common for enemies to materialize out of thin air, sometimes in response to triggered events. This does, however, happen consistently on the television show. Also irritating is the fact that you can't carry a one-handed weapon and a tricorder at the same time, since the switching of weapons and tools can sometimes be clumsy when rushed by an enemy.
There are also no difficulty toggles, for those less interested in the story and preferring more combat, and vice versa. Some of the puzzles in the game are good, but there are a few dopey ones, like the time you find a personal shield pack in the rafters of a Jem 'Hadar facility. Do the Jem 'Hadar strike you as the sloppy types that would leave something like that lying around? In general, most of the puzzles are also rehashes on the old DOOM formula of "find the blue key to get past this door" variety. In the Trek spirit, it would have been nice to have a bit more detective work involved.