Sev Zero review: Amazon's first Fire TV exclusive tested
Amazon's first big exclusive game for Fire TV is Sev Zero, which combines tower defense strategy with a third-person shooter.
Players start with an overhead view of the map, where they decide which fixed locations to place towers onto. Once ready, aliens start invading and players are dropped into the battlefield, having to blast away any alien creatures before they can make their way through the maze to the power core. You'll get some down time to upgrade and place new towers in-between waves, and will earn a cash bonus if you start the new wave before a timer runs out.
The weapons are rather standard fare, with the game starting off with a shotgun, sniper rifle, and machine gun. Of course, you can unlock new upgrades for them as you progress. Using a weapon levels it up, increasing its damage capabilities, and unlocks attachments. Attachments change the secondary fire for your gun, and you can have more than one equipped to switch between. These include upgrades like sticky turrets that independently target and shoot enemies, and Airstrike, which calls a missile strike down from your orbiting ship. The upgrades themselves can be leveled up from use, making them more powerful. Attachments keep the weapons from getting boring, but we wish that the loadout screen offered a more in-depth description, instead of having players figure out their capabilities and limitations on the battlefield.
Creatures in Sev Zero are pretty smart compared to what you'd normally find in a tower defense game. Once you're spotted, they'll stop their forward procession to attack you. Groups of them will try to surround you, forcing you quickly dodge teleport around the field. Larger aliens will cover their eyes, which ends up looking kind of funny, but it effectively shields their weak points from you. Some enemies will attack your defense towers directly instead of making a mindless run for the power core.
Continually switching from the field to the overhead screen, and beaming back on to the map takes a little getting used to. Oftentimes, it feels like we were snapped out of the action to do some quick maintenance before getting thrown back in. It can also be a little annoying when the system tells you that a turret is being damaged somewhere on the map while you're busy shooting an alien twice your size. It would be better if there were some sort of location identifier, so the player has some idea of how far away it is--especially if a turret is in critical condition and needs immediate attention.
Having a second player with a Kindle Fire will enable Dual Mode. By downloading the Sev Zero: Air Support app, friends can help out by using the tablet to fire missiles, freeze enemies, or drop traps. This unique brand of cooperative play emphasizes teamwork, as the tablet player focuses on support and ultimately working to supercharge the main player. It might not be as exciting as joining in the game as a second soldier, but it's a fun feature if you happen to have both the Fire TV and Kindle Fire.
Sev Zero gives us an idea of the gaming capabilities of the Fire TV box, and the launch game looks like it could have been released for the original Xbox. However, the production values leave a little to be desired. Mission debriefs are underwhelming, comprised of scrolling text with no voiceover. Maps also come off as a bit plain and drab. Any one part of the map looks almost identical to any other. Fortunately, the gameplay is fast enough so that you don't spend a lot of time checking out the background.
Although Sev Zero can be sufficiently challenging and exciting, it doesn't offer much that can't be found elsewhere. The fixed tower positions limit the game's strategic flexibility. And while the action portion is entertaining, it simply doesn't have much personality. The story isn't particularly engaging as well. What we end up with is a game that's fun for a while, but very easy to put down.
While Sev Zero doesn't have the originality or production to be regarded as a system seller, it's unquestionably a novel effort from Amazon Game Studios, and suffices in its role as "launch game." 
The visuals are akin to the original Xbox
This review is based on a copy purchased by the reviewer. Sev Zero is now available on Amazon.