The thing with the freebies is that we don't tell people in advance what we're going to give away for free, or no-one would ever buy anything :)
 

Having said that, we're unlikely to give those tiles away for free, as they are specifically for isometric games and we would like to keep the limited-time offers relevant to everyone (also people who don't care about isometric games). So animated characters, animals, and creatures are more likely.

We are also going to start a "free sprite of the week" program soon, so the freebies and limited-time offers will be more regular.