NiGHTS

For more information, see Nights (video game character).

Relation to Sonic
NiGHTS had helped Sonic free Amy and Tails from Eggman's hypnotism in Sonic Pinball Party. Otherwise, He's just a friend of Sonic's who makes cameos and playable appearances in Sonic games.

Sonic Adventure/Sonic Adventure DX Director's Cut
In Sonic Adventure, NiGHTS appears as a Pinball game. Her pinball game featured elements from NiGHTS into Dreams. Along with the NiGHTS Pinball, there was a Sonic Pinball. These cameos reappeared in the Director's Cut version for the Gamecube.

Sonic Adventure 2/Sonic Adventure 2 Battle
In the next installment of the Sonic Adventure series, NiGHTS made muliple cameos. In the City Escape stage, billboards and posters despicted ads for The NiGHTS Hotel, which can be seen in the sky lines of Shadow's Radical Highway stage. NiGHTS also makes a Chao cameo. The Neutral Fly Type Chao resembles NiGHTS, along with the Dark Fly Type, which resembles an evil looking NiGHTS.

Sonic Pinball Party
In Sonic Pinball Party, NiGHTS appears, once again, as a Pinball game. The Pinball game features many elements from NiGHTS into Dreams. This is the only game that NiGHTS gets a relationship with Sonic.

Sonic Riders
NiGHTS’ first playable cameo is in Sonic Riders. She can be unlocked if the player reaches certain requirements. NiGHTS’ board is called the Night Sky. Sections of the SEGA Carnival SEGA Illusion courses feature elements from NiGHTS into Dreams.

Sonic Riders: Zero Gravity
In the sequel to Sonic Riders, NiGHTS returns as a playable character. Also, in the 90's Boulevard course, you can see signs advertising NiGHTS and NiGHTS: Journey of Dreams.