You don't have to study its effect system in detail, there's not much to it. Instead of IO a you have Eff e a, where e is a record of effects, using PureScript's records support. The neat thing is that statements in the Eff monad tend to get compiled to x; y; z in the resulting JavaScript, which is great, you don't pay a performance penalty. Check out the source code in this demo: http://chrisdone.com/toys/elastic-collision-balls/ There is still some overhead for currying, but there's a lot of room for decurrying saturated calls.

You might be happy to hear there is a PureScript native compiler. I'm also averse to JS things, I use PS but don't use the node-based tools to build it.