Let's fill in those missing letters!

[Magma MK-II]

Might as well update the list with the systems previously mentioned:

* 3DS: Missing #, J, Q, U, V, X, Z (Game List)
* Atari: Missing #, L, O, Q, U, V, W, Z (2600 List, 5200 List, 7800 List)
* GameCube: Missing #, Q, X, Y (Game List)
* Nintendo Switch: Missing #, G, I, J, Q, T, U, V, Z (Game List 1, Game List 2)
* Mobile: Missing X, Y (iOS List, Android List)
* Neo Geo: Missing #, J, O, Q, T, U (H, X and Y does not apply) (Game List)
* Nintendo 64: Missing Z (Game List)
* PlayStation: Missing O, Q (Game List)
* PSP: Missing E, W (Game List)
* PlayStation 2: Missing #, J, Q, R, V, W, X, Y (Game List 1, Game List 2)
* PlayStation 3: Missing #, I, J, K, O, Q, R, V, W, X, Y, Z (Game List)
* PlayStation Vita: Missing #, A, B, F, I, J, K, O, Q, U, V, W, X, Y, Z (Game List)
* Wii: Missing Q, V (Game List)
* Wii-U: Missing #, E, I, J, Q, U, V, X, Z (Game List)
* XBOX 360: Missing D, E, F, H, J, K, O, Q, V, W, X, Y, Z (Game List 1, Game List 2)