RPS posted a news article on this last week, but I've just uploaded a new demo today which contains a massive chunk of the start of the game, from the intro story right up until the end of the first temple.

The gameplay is often referred to as a mix between The Legend of Zelda, Metroid, and the Dizzy series. It contains the temples of Zelda games, the power-ups and abilities of Metroid, and the item-based puzzles of the Dizzy games. It also features a switch mechanic to toggle control between Spud and Prince Charming, in which teamwork is used to progress.

Get it at the Spud's Quest website