Sorry if any of these have been pointed out before:
-Sonic & Knuckes' game icon is a screenshot of Sonic 3.
-Vampire Killer (1986)'s game icon is a screenshot of Castlevania Bloodlines. This is understandable, as Bloodlines is called Vampire Killer in Japan.
-Sonic 3D Blast (Saturn)'s game icon is a screenshot of the Genesis version.
-Sonic & Knuckes' game icon is a screenshot of Sonic 3.
-Vampire Killer (1986)'s game icon is a screenshot of Castlevania Bloodlines. This is understandable, as Bloodlines is called Vampire Killer in Japan.
-Sonic 3D Blast (Saturn)'s game icon is a screenshot of the Genesis version.