Kingdom Hearts is a video game series produced by Square Enix as a collaboration with Disney. The games feature many characters from the Disney franchise and characters from Lilo & Stitch have appeared throughout the series.
Kingdom Hearts II
Stitch first appears in Ansem's study climbing the walls before falling on the computer keyboard and then jumping off as Donald tried to attack him. Later on in the game he can be used as a summon to aid Sora where he shoots enemies and plays his ukulele to stun them.
Kingdom Hearts Birth by Sleep
Set in Deep Space before Stitch has landed on Earth, when Terra arrives he is placed in a prison cell where he breaks free and meets Jumba who he frees from his cell to help him find Stitch. After Stitch is found, Jumba releases Experiment 221 to fight Terra in order to prove experiments don't have hearts. Later, Aqua appears and meets Gantu who takes her to the Grand Councilwoman where she is told to capture Stitch and Jumba. When the two are found, Gantu attempts to destroy them but they successfully fight him off and the Grand Councilwoman demotes him. Lastly, Ventus arrives and escapes from Gantu with Stitch who travels separately in his red cruiser.