As an aside, calculating obstacles to water is a pretty big deal - it's why you almost never see it done, and it results in huge slowdowns due to CPU load if they do. It's a tradeoff between realism and playability. I'm not 100% happy about it, but I think it's necessary until someone figures out a way to do it more effectively. In almost all other respects, valheim chooses the 'heavy' approach - it's why the graphics are a tad low detail. But it means you have boats you can actually walk around on while they move - you don't see that often. Or buildings that behave much more like buildings in the materials they are built from, etc - and you still can modify the landscape, too.

Can anyone think of a survival game where sea water actually is modeled to be affected by player made structures? It would be pretty cool - let you build water mills and so on - but I don't think I've seen one.