The only thing I dislike about Lua is the 1-indexing. I know they had reasons for it but it always caused issues.
Initially I agreed, just because so many other languages do it that way.
But if you ignore that and clean slate it, IMO, 1 based makes more sense. I feel like 0 based mainly gained foothold because of C's bastardization of arrays vs pointers and associated tricks. But most other languages don't even support that.
You can only see :len(x)-1 so many times before you realize how ridiculous it is.
Having written a game in it (via LÖVE), the 1-indexing was a continued source of problems. On the other hand, I rarely need to use len-1, especially since most languages expose more readable methods such as `last()`.
What does bug me is that Lua, the language, is 1-based, but its C api is not.