Well, I'd say it is worth playing for two reasons:

(a) On its own merits, as a wonderfully weird map. Really ugly (especially the final arena-ish area), but certainly interesting nonetheless.

(b) Because (to me at least) it is interesting to see where a master mapper such as digs started.

This is like one of those poorly made but very creative beginner maps, where you wish the author had kept mapping, so that their skills could catch up with their creativity – only in the case of digs, that is exactly what happened.

Are we sure the "Digs" who made this map is the same person as the Digs we know from more recent maps? I ask because as well as this "digs2", the archive also contains "digs02", which is completely different: https://www.quaddicted.com/reviews/digs02.html

Anyway, if this is the work of real Digs, I agree it shows seeds of promise. It's a fun blast, with a few interesting surprises. I am a bit disappointed that I never found a good use for the gold key, though.