So, I have now completed the entire Magical Quest trilogy.
Magical Quest 3 is pretty much more of the same, except with an additional twist. Mickey and Donald play slightly differently. The outfits they get have the same functionality but have their own quirks.
The armour outfit, for instance, Mickey, has a lance and shield, whilst Donald is in a barrel with a squishy hammer... Someone is loved more than the other, and that one is Donald. He is strangely overpowered in this game.
This game literally throws extra lives at you, possibly because the expectation is you'll be playing Co-op and much like MQ2, dying drops you straight back in the action, none of that pesky restarting from the beginning until you need to use one of your infinite continues.
Again, like MQ2, using a continue means you lose all your coins. But this game has a repeatable mini-game to make coin farming a little less tedious in some areas.