sonic & knuckles

An entry in Sonic the Hedgehog series for Sega Genesis and the 2nd part to Sonic the Hedgehog 3 game.

With its unique shape of cartridge called Lock-On Technology, it can be inserted between other cartridges, which allows to combine the two-parter into the intended form.

This tag implicates sonic_the_hedgehog_(classic) (learn more).