I think that Solutions page is quite useless right now. Yes, you can see different approaches people used but you have no idea which of these approaches are actually better or whether there are much better solutions which just haven’t been upvoted yet. The whole upvoting system is broken since most people only look at top 10 solutions and those are already the most upvoted ones so solutions with zero upvotes usually go completely unnoticed.
I propose adding three different ways of sorting for the Solutions page:
By upvotes. No different than the current way.
By characters count. One of my favorite things to do after I solve some puzzle is to search for the shortest solution. Short solutions usually fully exploit the power of used programming language and are a great learning material for those striving to be better programmers. I wanted to propose LOC metric first but then I figured out people would just put 1000 characters in one line where possible (not applicable to languages which use indents heavily like Python but you can make a one-liner from any source code in C++).
By execution time / efficiency. This would be a great way to learn new algorithms. Also it would turn every puzzle on CodinGame into an Optimization challenge with people trying to make their code as efficient as possible. Memory can also be used as an efficiency metric.
This might mean adding new validators where execution time matters.