Sea of Stars

Wheels is a unique mini-game that you can find in most town taverns. The basic gist is that you will select two playing pieces that have different abilities, then spin a wheel up to three times while choosing to "lock" certain symbols after a spin if you want to keep them. The symbols with the stars on the background will go toward leveling up your pieces (bronze>silver>gold) and doing so will make them more powerful. The basic symbol relating to sun or moon will power up the pieces on the left or right respectively, to perform whatever action they can do (attacking, healing, interrupting, etc), while the hammers will build a defensive wall in front of your castle. Once you make enough attacks to reduce the health of the enemy castle to zero, you win. It makes much more sense after playing a game or two.

I personally found using the Mage and Archer a solid combo every match, as the archer can shoot over walls, and the mage attacks twice to knock a wall down and still get in damage with the second attack (or two damage attacks if they have no wall). Your first match will be the hardest since that is where you win the Archer piece. Other pieces may have stronger attacks, but you're often thwarted by the enemy building a wall on the same turn you attack, or using an Assassin piece to interrupt your attack.

To unlock this achievement you'll need to defeat the Watchmaker in a game, and you'll need to defeat every other Champion player in the game first before you can challenge him. Below is a list of where you can challenge each player.
 

The rewards for defeating each Wheels player are locked in order, so no matter which one you defeat you'll always get the next reward in line. These are as follows: