ZZT. It’s one of Tim Sweeney’s (Of Epic fame) early games. It was my intro into true OO programming. You program literal objects to interact by message passing

ZZT. It’s one of Tim Sweeney’s (Of Epic fame) early games. It was my intro into true OO programming. You program literal objects to interact by message passing. You should be able to pick it up all over the internet. It’s abandonware but has a pretty good community.