1. I show you the full Node class, so why do you complain about it ? You identify the node by the object id, it is enough.
2. I overwrite the Hash methods because you should no use them, if you write your own hash-like class YOU'RE DOINT IT WRONG.

"Thanks to shadchnev, I broke all of the methods from the Hash class."

3. You don't need a method create_chain that's why codewars is here just type your code in the browser and run the tests.
4. OBJECTIVE : Your objective is to determine the length of the loop. -> How can it be more clearer ?
5. Use the function #next to get the following node. -> means do not touch the nodes and use the object id to compare the node.
6. The code is runned on their servers so the timeout is due to your connection or bad solution