This one is the same variant as I described previously: all the numbers are outside the loop. This one is larger at least. I don’t know whether it’s actually more difficult other than that.
One aspect I particularly appreciate of well-designed slitherlink puzzles (and this type of puzzle in general: masyu, nurkabe, fillomino and others) is that there is only one solution. This leads to the interesting solving technique that if a proposed addition to the work-in-progress leads to a situation where there are two ways to fill in a section and both are equivalent, then the proposed addition must be wrong, because there cannot be two solutions. This technique is particularly hard to apply, but I’d be very interested in a puzzle that required extensive application of it to find the solution.
In any case, here’s the puzzle. Check the previous post if you don’t know the general rules for a slitherlink.