I had those! I fear that my mother may still have some of my creations coasters, even. I just didn't remember what they were called and had, in fact, forgotten all about them until just this very second reading your comment. OMG, wow, a wave of the early 90s just swept right over me.

You should definitely make something with the ones you found! The world needs, like, a little pixelated David Mitchell eating pizza or something. (I have just horrified myself with this sentence. But in the best way.)