Unseen Diplomacy was the first game ;) And they (Triangular Pixels) are working on Unseen Diplomacy 2. Follow them on twitter or join discord.
Tea For God is going to be sort of open world. Sort of because it won't be truly open world. Where you can just wander endlessly. Lots of stuff here is experimental and I don't want to go to crazy with it. This is also a reason why it won't have realistic graphics, everything is procedurally generated, it has to be done quickly, etc. I decided to not go into texturing, just getting meshes geometry is enough for now. But getting back to open-worldness. There will be a map of the world. I plan to allow choosing where do you want to go next. But every such trip will start and end at a station where you can buy/sell stuff etc. Lore will explain more about why it looks this way, why there are impossible spaces, etc. Most likely getting back on the same path you will get the same level (repopulated, at least partially). So it won't be just a tree/graph as in other roguelites. And for sure it won't be a linear thing.