We just innocently try to make a PC port of Slam Bolt Scrappers for Steam (coming 3/14) and next thing we know we have two new unlockable playable characters sneaking into the game. (firehosegames.com)
Other unlockable playable characters include FN - 1044 (Stormtrooper), Jashco Phurus, Rosser Weno, Stormtrooper Officer, Strono Tuggs, Thromba, Laparo, Jakku Freighter (Full - size and Microfighter Vehicles). (thehdroom.com)
Dry Bowser appears in Mario Tennis: Ultra Smash as an unlockable playable character. (mariowiki.com)