Townscaper is a nice one like this; it has very few features or gameplay, just a sandbox tech demo for a very cool take on model synthesis / "wave function coll

Townscaper is a nice one like this; it has very few features or gameplay, just a sandbox tech demo for a very cool take on model synthesis / "wave function collapse" on an irregular grid. The game is mostly carried by the novelty of this mechanic (and also the pleasant art.)