Thanks for playing! I'll have a look into it being compatible for every browser. The later levels spawn the socks at a random location each time, maybe it just happened to do the same location a few times in a row :/ , but thats something I can fix so thanks for pointing it out!
Repeated sock locations is fine! What I mean is that the player knows the socks location before running the code, and so you can hardcode "forward, right, forward, forward" as an example and win. If you instead shuffle the socks location upon pressing "Run", the player would have to write a proper solution. Another example would be a snake game where upon picking up the socks, a new pair appears, and so on. Lots of fun ideas!