David Crane's The Rescue of Princess Blobette Starring A Boy and his Blob

This unusual game is a mix of action and adventure. You control the Boy, who is accompanied by the very versatile Blob. Your goal, of course, is to rescue the Princess Blobette from a large castle. In order to do so, the Boy must use the Blob to get past the castle's many obstacles. The Blob is an extremely useful creature. By feeding it jelly beans, it will turn into useful things like a trampoline, ladder, or key.