Currently, there are only seven handheld devices (excluding the Game Pad of the Wii U) that Nintendo has released. They are listed below with a brief description along with what Donkey Kong games are playable.
Game Boy Color- basically a remake of the Game Boy; has three times as much memory, and has a screen that can project color. Donkey Kong Country, and all of the other games on the Game Boy are compatible with this system.
Nintendo DS- has a flip screen like the Game Boy Advance SP; has two screens, one for the bottom half, and one for the top half. The bottom screen features a touch screen. The system comes with a Stylus, a pen-like pointer used on the touch screen. Mario vs. Donkey Kong: Mini-Land Mayhem!, Mario vs. Donkey Kong 2: March of the Minis, and DK: Jungle Climber are all playable.
Nintendo 2DS- almost exactly similar to the 3DS; has a flat face (no more flipping of screens like the Nintendo DS and 3DS), has a mono speaker. All games from the DS and 3DS are playable.
New Nintendo 3DS- an upgraded version of the 3DS; possesses larger screens than the 3DS, making it easier to see the 3D effect. Also has better image and has stereo speakers. All games from the DS, Game Boy Advance, and 3DS are compatible.