I just ran this as an intro to OSR-style games for my 5.5e group. Everyone loved it!
Tips for anyone running this: it was a little tight for a 3.5hr one-shot. Expect 1-2 sessions of gameplay. I used Shadowdark (with 3rd-level PCs) and had one character die. Most of the traps and hazards could one-hit kill my party, so make sure to telegraph the danger so it feels fair.
Overall, I highly recommend this adventure!