Advance Wars 2
  
Game Boy Advance
  

Nintendo Map:


  At the Design Maps/Map or CO screen, highlight Map and hold A + L + R. The
    screen will go blank, then the Nintendo map will appear. 
See AW2 Pictures:


  At the Sound screen, press Select to check out game pictures. 

 Adder:


Beat all  Black Hole campaign levels.

Colin:


Buy Grit or Olaf at the store. 

Drake:


Beat  all  Green Earth campaign
levels.

Eagle:


Beat all  Green Earth campaign
levels.

Flak:


Buy Flak in Battle Maps.

Grit:


Beat all  Blue Moon campaign levels.

Hachi:


Beat  all  Hard mode campaign levels, or buy everything in the store. 

Hawke:


Beat all  Black Hole campaign levels.

Jess:


Buy Drake or Eagle at the store.

Kanbei:


Beat  all  Yellow Comet campaign
levels.

Lash:


Beat all  Black Hole campaign levels.

Nell:


Beat  all campaign levels.

Olaf:


Beat all  Blue Moon campaign levels.

Sensei:


Buy Kanbei or Sonja at the store.

Sonja:


Beat all  Yellow Comet campaign
levels.

Sturm:


Get an "S" rank overall in the campaign.


Thanks to Revolution readers Josh Ustead, Markish, rufus33 and joybuzz!