Gosh, this one is stressful. But figuring out how to get to deliver poison is satisfying. I haven't managed to poison all five storages, but I think I might be getting there. I don't know if that's intended, but seems rushing next to the spiders is a must. Will try to beat it anyway.
The music definitely fits the gameplay and helps a bit. It's a bit dark, but I assume that's deliberate. However, navigation can be a bit confusing and the limited view makes it harder to plan a route. Sometimes a spider is behind a corner and there's no tell for that. I'm not sure about one thing, but I'd assume there are two enemies per storage, right? The counter for them doesn't seem to always go down.