Fun twist on the defense genre that makes you think in a different way! The ability to move in only one direction changes the gameplay in ways that shouldn't be underestimated. The little touches on the mechanics really added to the experience for me; the little bit of lag time where the wagon still fires after picking it up, the slowdown on the edges of the curve, the ability to body block some of the enemies -- all minor, but when taken together create a satisfying game.