Is this usable on unity?

Your Art is amazing! I'm currently working on an RPG in Unity and am loving your tile-sets. I do wonder why this one offers 48 x 48 but not of your other art (that I've seen) goes above 32 x 32. Also the cylindrical tower beside the 2 x 2 dark castle, I wish there was an alternate top piece so that we could extend the tower to be as tall as we want. 

It says "It can be used other than game development" so does that mean it cant be used in games?

Keep up the good work! I hope to be able to support you in the future.