Melonchi Minecarts is a fun puzzle game based in the mineshafts of Arvale (I'm not sure where that is, exactly) with great animation and a nice story. You can play as one of three characters - Duncan, John DeMenchev or Grwyth the Dwarf - each with own peculiar personality. At the start you can choose to follow the story mode or get straight into the action.
The game is simple enough. You are in a minecart and must collect the precious jewels on the track. Collect them all and you move on to the next level. Of course it's not as easy as that. As you move along the track it explodes, meaning that you can't go retread your path. Before stating out you must navigate the only possible route to get the jewels without destroying the track. It's fairly challenging and good fun. The only problem I had was that the game loaded up horizontally making the controls more challenging.