After the not particularly impressive Evil Dead from Palace, Cauldron is a breath of fresh air. My original impression is of a Defender type, scrolling screen, with superbly detailed forests, graveyards, islands, and other bits and pieces running across the bottom of the screen.
However, instead of a spaceship you have a witch, and instead of aliens you have bats, ghosts, sharks, and other various nasties. It is here that the similarity with Defender ends. Whilst you are blasting (sorry, casting spells) at the baddies you must look for some keys, a key of one particular colour will let you into a door of the same colour. There are four keys and eight doors.
Entering a door changes everything. The game now moves on to a ladders and ramps type game, but I found it much more satisfying than most L&R stuff as it has a much more interesting style and some puzzles extend over many screens.
Completing the room rewards you with an ingredient for your spell. Collecting six of these and dumping them in the pot in your cottage rewards you with a spell, with which you can get rid of the giant pumpkin in the final room. No mean feat at all.
The instructions are presented in verse. Buy this game without delay, shift/run stop, and then press play.