In the "Skins" menu there is an option to select Jak in his Jak 1 clothes from the Jak and Daxter series. However, only player 2 in "Co-op mode" can use it due to Ratchet and Jak being dimensional rivals counterparts.
Contributed by ProtoSnake
In a demo for the game, the music of Team Darkstar's containment suite was used in the second mission of planet Shaar.
Contributed by ReakMayhem