I supported this on Kickstarter, and I just ran my first session of A WIZARD. I'll have to say, without hyperbole, this is one of the coolest, most fascinating, and best modules I've ever read in my 20 years of DMing. I think this would fall in my top three favorite modules. But accolades aside, I'm torn how to review this without spoilers; part of the joy I got from this module was simply to read and discover the wizard's tower.
The tower itself has great encounters that are briefly, succinctly, and imaginatively written, allowing for a lot of improv and exploration. The tower doesn't have random encounters, and other typical OSR elements, instead drilling down to the weird, and focusing on wet, raw horror; we started playing as OSE and the game felt like Mörk Borg by the end of the session.
There's a delicious internal commentary the WIZARD shares with the DM; things are definitely NORMAL and very OKAY. Disobedient apprentices get WHAT THEY DESERVE. This creature has a perfectly NORMAL AMOUNT OF LIMBS...etc
I'm a cheapskate at times, but I will tell you that the $8 (current price) is far too low. The quality of the writing and art is worth much, much more. I'd love to see this embellished further in the future, expanding the town, enriching those NPCs, and incorporating the abyss better (e.g.: what if the players become apprentices? Or, where did the WIZARD come from? The abyss could be used to flesh that out more).
But if you like horror (gore, body horror, suspense), like to mess with your players, and have a visceral good time, BUY THIS MODULE. (Disclaimer: I have no financial ties; I just was really dang impressed with this module).