Allegiance is an impressive online game that fuses space combat simulation with elements of strategic military planning and command. It's exclusively playable online, and while it has an interesting premise, there's no real context to the actual battles you'll participate in. If anything, its lack of a single-player campaign merely clarifies the distinction between Allegiance and all other space combat sims - its real-time strategy elements and its focus on cooperative piloting tactics are so central to its gameplay that Allegiance can be very challenging to learn, but it's well worth the effort.
Allegiance's depth and complexity are veiled by its clean, effective graphics. At most times during play, you'll be looking at your ship's first-person heads-up display, which depicts all pertinent information regarding your ship and your surroundings. Like many aspects of Allegiance's interface, the various readouts on your HUD aren't particularly intuitive - it'll take some time to be able to distinguish all the onscreen indicators. However, after you spend some time flying around in the game, you'll find that the initially overwhelming amount of information on the HUD is actually presented very well. Allegiance's minimal HUD graphics leave plenty of room for all the dozens of different indicators you might see onscreen at any given time, which point to all friendly and enemy ships, as well as miscellaneous space objects, missiles, stations, and more. There's a small space left up top for communications between players, and a floating minimap, which you can toggle off, that shows you where you are relative to the rest of the battle. It's a lot to take in, but Allegiance's graphics do a great job of presenting all the relevant information you need without actually cluttering the screen, which leaves you with a perfect view of the game's impressive 3D space combat.
Allegiance's 3D engine is surprisingly good. The various ship designs are attractive and original, and Allegiance's version of outer space is filled with bright-colored gasses, plenty of stars in the distance, lens-flare-casting suns, gigantic tumbling asteroids, and more. The ships are highly detailed and have pulsing warning lights on their wingtips. They leave long, colored contrails in their wake, which provide a useful visual cue in the heat of battle. They burst into big, bright explosions but don't leave a lot of debris behind. In fact there's very little visual excess in Allegiance - the game's weapon effects look fairly simple, while the game's special effects for wormholes and such are attractive but never gaudy. Allegiance can sometimes look a little sterile as a result, especially since all the ships look similar from the inside. But it's all worthwhile when you get dozens of ships flying around all at once with a smooth frame rate and typically without much lag.
The game's no-nonsense graphics are complemented by its clear but generally forgettable audio, which provides spoken cues for important events on the battlefield. You're able to issue preset verbal cues yourself with just a couple of keystrokes so that you can quickly request assistance, give orders, or even taunt your opponents. Some of the sound bites are pretty funny and thus inconsistent with the game's generally serious tone, but you can toggle off the speech if it bothers you. In contrast, the game's symphony-and-techno musical score is suitably intense and dramatic.