This is my first ever video game review, so bare with me. :P

Code Name: S.T.E.A.M. for the Nintendo 3DS.

Code Name: S.T.E.A.M. is a third person shooter turn based strategy game by the creators of Fire Emblem. Like Fire Emblem, it can be hard to near-impossible in turms of difficulty, so if you like easy games, this is not the one for you.
The game is slit into chapters, with each chapter having 2-3 maps. Each map is split up into a grid, with each unit unit moving around separetly. You begin the game with only one character, but over the course of the game you unlock many more, totaling at 12 unique characters, each with there own weapons and playing style. Each map you select up to four characters, with the game helpfully having a reccomended set for when you're not sure what to expect. Each time you recruit a new character, the following map seems designed to show off their unique skills, which is great the first time, but replaying any of those levels pretty much forces you to use that specific character, limiting you strategies.
Once you have your characters selected, you may pick a boiler and sub-weapon for each one. The boiler's are like armour, giving different stat boosts, and changing the amount of Steam each unit can hold. They are unlocked by collecting coloured gears hidden in each level. The sub-weapons are weapons that can be used by any character, allowing each one to be more versatile. For instance, one character has a weapon that heals anyone it hits, but can't attack foes with it, so you can give them a damage dealing sub-weapon for if they need to fight.
As for the gameplay itself, each character has Steam, which is used whenever any action is taken. Moving one square on the map uses up one point of Steam, while firing you weapons use various amounts of steam depending on the power of the weapons, with missile's costing four points, while a weak shotgun only costs two. While the game is turn based, the movement is done in third-person over the should view, and the attacks have to be aimed manually, so if you miss, it's not because of a random number generator, but because your aim was off. The aiming controls take a bit of getting used to, but the enemies are more forgiving for the first few levels to make up for it.
Though the game is split into turns, some weapons and enemies can go into Overwatch, where they will shoot at anything the passes into their range duing the enemies' turn, provided you have enough left-over Steam to fire it. While this is useful to the enemies, I found myself rarely using it, prefering to deal as much damage as possible during my own turn.
Each character, ally and enemy alike, has a weak spot which does extra damage if it is hit, shown as a glowing purple patch. You will find youself aiming for at all times, especially once you get the Steam Crossbow, an early sub-weapon that deals much less damage to enemies tha most others, but does three times the damage of other weapons upon hitting a weak point. Though the player characters also have weak points, the enemies rarely take advantage of them, prefering to overwelm you with regular attacks.
In each level, there a coins to pick up, which can be used to unlock sub-weapons, or active mid-map save points.
Once a character runs out of Hit Points, they are gone for the rest of the map. But at certain points at the map, there are single-use save points, where you can spend coins collected in this level to revive and heal all your fallen comrades. These are suprisingly useful, as they also restore each character's Steam, allowing them to effectivly move twice in one turn.

As for the story, it is framed at the begining as a comic book, and the cutscenes are shown as though they are animated panels of a comic. The story is about a group of literary characters like Tom Sawyer and the Cowardly Lion, teaming up with Abe Lincoln, who had faked his own assasination and started a secret organization to fight off a possible alien invasion. The story is quite strange, and like most ongoing comics, it doesn't fully tie up all the plot threads by the end, but overall it's ok.

Though the game will work on a regular 3DS, the New 3DS has a few upgrades that make the game better, such as a second circle pad for aiming, and the ability to speed up the enemy turns to three times as fast as normal, as opposed to only two times on the regualr console. Also, if you have the New3DS or the Amiibo adaptor, the Marth, Lucina, Robin and Ike Amiibos will each work with this game, unlocking the respective character for all levels. Unlike all the other characters, the Amiibo characters cannot be revived by the save points, and must be scanned back in at the start of a new map, causing you to be more careful with them. To make up for it, Lucina and Robin are the two strongest units in the game, while Marth is a useful scout. Ike is pretty much useless. Another fun addition is that if you have a party of all four amiibo characters, the map music will change to remixes of various songs from Fire Emblem games.

Overall, if you don't mind a hard game, Code Name: S.T.E.A.M. is a pretty good strategy game. And it's not that hard to get a copy of it, with it going as low as Ł10 at times. (And no, I'm not giving you numerical score, cause I don't like those.)