I don’t know what I enjoy the most: the game, or that the title says “chapter 1”, which suggests there’s more to come :-)
You depicted quite well one of my fears: lonely swimming pools.
Let me suggest something that I would find very eerie: big pools that can be drained, and that they are misteriously filled again after some time, suddenly seeing streams of water coming from the treatment system holes (as a shocking surprise you don’t expect). Also, walking at the bottom of an empty pool, and not being able to get out of it because the pool walls are tall and the stairs are at their top: only when it’s filled again, you’ll reach the stairs and get out if it.
It’s just a suggestion, in case you like it.
Also, I love that it doesn’t need to be installed. Please, when you release the final game (or any other future chapters), don’t make it depend on the steam loader, nor require any installation at all. Ship it just like this beta.
You have a fan in me. I want all future versions you release :-)