Famicom Wars (or Nintendo Wars/Advance Wars) is a series of military turn-based and real-time strategy video games usually developed by Intelligent Systems and published by Nintendo. The series debuted in Japan on August 12, 1988. Like another Intelligent Systems series, Fire Emblem, most games in the series were released only in Japan; Advance Wars (2001) was the first to reach the North American and European markets. Advance Wars was released in the USA on September 9, 2001, but put on hold in Japan and Europe.

The player takes the role of Commanding Officer (CO) in an army, usually of a country called Red Star (Orange Star in Western releases). In the single-player campaign of the Advance Wars games, each level consists of a new map and opposing CO to defeat. Victory is achieved when all of the opponent's units have been destroyed, their HQ is captured, or another victory condition has been applied.
(Wikipedia)

UNLOCKABLES

Bonus COs

Adder (costs 1,000 points)
Win mission 26 in normal campaign mode.

Candle (costs 3,500 points)
Win mission 26 in normal campaign mode.

Chakka (costs 3,500 points)
Win mission 26 in normal campaign mode.

Flak (costs 1,000 points)
Win mission 26 in normal campaign mode.

Grimm (costs 1,000 points)
Win mission 20 in normal campaign mode.

Hachi (costs 2,000 points)
Complete normal campaign mode with an overall "S" rank.

Hawke (costs 1,000 points)
Win mission 26 in normal campaign mode.

Javier (costs 1,000 points)
Win mission 20 in normal campaign mode.

Juggler (costs 3,000 points)
Win mission 26 in normal campaign mode.

Kindle (costs 3,500 points)
Win mission 26 in normal campaign mode.

Koal (costs 3,500 points)
Win mission 26 in normal campaign mode.

Lash (costs 1,000 points)
Win mission 26 in normal campaign mode.

Sturm (costs 5,000 points)
Unlock all other COs, their color edits, and earn all 300 medals.

Nell (costs 2,000 points)
Complete normal campaign mode with an overall "A" rank.

Sasha (costs 600 points)
Win mission 20 in normal campaign mode.

Von Bolt
Complete hard campaign mode.

Zipo (costs 3,000 points)
Win mission 26 in normal campaign mode.

Battle Map Shop bonuses

Insert either Advance Wars or Advance Wars 2: Black Hole Rising into the Game Boy Advance slot on your Nintendo DS before powering up. Once in the game, go to Hachi at the map shop. He will comment on your taste in games and will have a new wallpaper that will cost 1 credit, which may not otherwise be available in the game.

Advance Warpaper (costs 1 point)
Have the Game Boy Advance game Advance Wars inserted.

Advance Warpaper 2 (costs 1 point)
Have the Game Boy Advance game Advance Wars 2 inserted.

Hachi's Land map (costs 1 point)
Have the Game Boy Advance game Advance Wars inserted.

Lash's Land map (costs 1 point)
Have the Game Boy Advance game Advance Wars 2 inserted.

Nell's Land map (costs 1 point)
Have the Game Boy Advance game Advance Wars inserted.

Strum's Land map (costs 1 point)
Have the Game Boy Advance game Advance Wars 2 inserted.

Other bonuses

CO Edit
Reach level 10 or higher with a CO. An alternate costume option is in the CO Edit menu.

Gallery (costs 2,000 points)
Complete normal campaign mode.

Mistwalker
Complete hard campaign mode.

Oozium (costs 1,000 points)
Win mission 22.

Soul of Hachi
Complete hard campaign mode.

Soundroom
Complete normal campaign mode and buy everything from Hachi.

Wallpapers
Complete campaign to unlock wallpapers for the three COs used most in that campaign at the Display menu. Get all 300 medals to unlock the final wallpaper.

Here is a Famicom Wars commercial: