Rock of Ages

Fun little game that I got from Plus. You roll a boulder down a hill towards the enemy fortress, knocking down their shit along the way to earn money. When you hit the fortress you have a short time to build reinforcements on your own hill, using the money, while another boulder is being built. You can also upgrade the boulder and stuff.

It's half tower defence, which I don't normally like, but the other half involves rolling a giant bolder into expensive shit, so it's okay.