Sometimes server sends a simple packet and client simply responds immediately. This is called pinging and is used to check if the client is alive, and the response time. For normal gameplay this value should be below 200ms, however the game should also work with higher values.
Yeah, the game is still in the development. Sometimes when a worm crashes to another worm it will not stop, but it will cross over and continue instead. We are working on it, just wait and see ;)