Minimally usable by my standards.
Handles simple routes, routes with parameters, static folders and files, etc.
Performance is great, although it shouldn't be a priority. Simple code is just fast I guess.
All manual testing on the GET method seems to indicate it is working. Further testing will be necessary but I will have to do that ad-hoc.
I do not recommend using in production environment yet, but I surely will, it's a good way to check if there are any bugs, security issues or memory leaks in long-running scripts.