Twice the power, half the fun
Both feature Mickey venturing into said castle to rescue Minnie from the evil with Mizrabel and similarly-themed levels, but virtually everything beyond that point is different. The MS version actually feels like you're exploring a castle while the MD version feels more disconnected.
I've always preferred the sequel, World of Illusion more, but CoI is a fine game that deserves its regard as a classic, however fleeting.
Graphic B Sound B Gameplay B- Lasting Appeal C+