Tower defense is an offshoot of the real-time strategy genre that seems tailor-made to appeal a broader audience. Paths for enemies are premade, and by proxy, so is tower placement. Resource management is already handled, and your only worry is your main base. Once you figure out which kind of tower needs to go where and if you're quick to react to any changes, you can pretty much relax and watch the carnage unfold on the map. With so many tower-defense titles released over the years, both free and paid, you have to wonder what a new game in the genre would do to stand out. In the case of Siege of Centauri, the answer is not much.

Siege of Centauri is a spin-off of Ashes of the Singularity, so the story will be very familiar to fans of sci-fi. Humans have finally colonized a planet outside of the known solar system, and peace has reigned for years. It doesn't take long for that peace to be broken due to an invading force that has taken out those colonies left and right. In response, Earth has sent some ships to rescue colonists who are still alive, and the ships have the approval to use deadly force if necessary.

From here, the gameplay should be familiar to anyone who's played a tower-defense game. Maps start off with indicators of where enemies will be marching in from and the set pathways they'll take to your base. Each pathway is conveniently flanked by high embankments that are perfect for tower placement. Your towers have standard abilities, like being able to do damage, go after multiple targets at once, do damage over time, or gather up scrap if an enemy is destroyed in its vicinity so you can get your resources faster. Beat any of the game's 24 stages, and you'll receive a new tower to use for the next skirmish.

The game sports a few things that aren't seen in too many other tower-defense titles. Instead of having all of your towers at your disposal at any time, you need to select which ones you'll take with you before starting your mission. There's a limit of 10 types, so you need to do some planning before the action starts, and the game helps by showing which enemy types will appear in the mission. Upgrades can also be done here, so your only involvement with towers on the field is to place them and sell them. To balance things out, you can initiate some powers on the field, such as adding troops to slow down enemy forces or a large mech to dole out extra damage. While tower placement is still handled by grids, the grids are so small that you have some freedom over tower placement, since you can make minute adjustments so everything fits perfectly. Finally, Siege of Centauri also gives you alternate targets to protect.

These additions sound exciting, but once you get into the game, the excitement doesn't last. It isn't that the title is boring so much as the difficulty increases at a good clip, and you'll need to react quickly when you've discovered that the enemies are going after an ancillary target instead of the main one. It feels like you've seen and done this type of thing before. Successful tower-defense games manage to feel distinct from the others. That doesn't happen in Siege of Centauri, so unless this is your first tower-defense game or you love the Ashes of the Singularity universe enough, there isn't much here to get you to stay and finish the title, unless you love the genre in all forms.

Beyond the campaign, you can dabble in a few other modes. Endless mode is exactly what it sounds like, and while it can get challenging as you progress, it isn't something that people tend to clamor for in this genre. You can play maps that were created by others, and while you won't expect an immediate user-made map flood, but there's the hopeful presence of a few maps. To that end, the map-maker is rather dense, so the inclusion of a thorough manual is appreciated, and there's certainly enough depth here to craft something that looks quite good overall.

Speaking of looks, the presentation is very nice. Despite being set on a bunch of barren parts of the planet, the environments look fine, and there's a good amount of detail in things like moving trees and bubbling lava should you decide to zoom in on those parts of the map. Most of the enemy units and your own towers aren't that exciting to look at, but they sports some nice details, and the game does a good job of handling the abundance of on-screen units without slowing down. The same goes for the particle effects from laser blasts and explosions, which are also eye-pleasing. Sound is a bit less impressive, as the effects are fine and the music is forgettable. Even though the story is something that most people will skip over and the warnings might be ignored, at least the vocal performances are well above average, considering the game's spin-off status versus the mainline series.

Ultimately, Siege of Centauri is fine. Its mechanics are solid enough, it does everything else decently on-screen, and the pyrotechnics are spectacular to see. It just doesn't feel like anything special, from the abilities to the story to the units to the towers. It's the kind of game that you wouldn't mind playing but won't rush out to buy immediately, making this difficult to recommend unless you devour every game in the tower defense genre.

Score: 7.0/10