Like others, I find the say() function quite useful for debugging, though it can get you killed before completing the goals due to the delay.
A think() function that displays recent debug info in a thought bubble would be great, if the time cost was sharply cut down.
I’m agree with you, a way to debug is needed. But I’d prefer a real debugger like we had in few levels in the pre-history of this site.
You was able to step by step your code and review with a hover the values of all variables. For me, a must have, and a long awaited feature.
That would be even better, definitely 
I just want them to get the code debugger working and implemented. (they have a super nice debugger but its disabled because it was buggy)
They should write a debugger to debug the debugger 
I like the idea of a think() function that doesn’t cost time. I think the educational value is great also, because that’s actually similar to how people debug in real life. (short of using an actual debugger, of course)
While we’re wishing, it would also be nice to have a slow motion option when clicking “run”.