Needles at "Swords & Stitchery" gave a very detailed and enthusiastic review. I loved all the ideas presented in the review about how to integrate the Fungus Forest into different genres - great stuff! You should read the whole review but the last paragraph has a nice summation:
"So why all of the serious fungal talk about the Fungus Forest adventure? Well because it happens to include a full OSR monster tool kit for creating your own fungus monsters and encounters;"Ready Reference Appendices: Formatted in black and white with printable margins to enable home printing for easy in-game reference; Appendix I - Random Fungus Generator; Appendix II - Magic Mushrooms of the Fungus Forest; Appendix III - Fungus Forest Bestiary (30+ unique entries); Appendix IV - Printable Fungus Forest Map." This makes inserting the Forest and its monsters into your old school campaigns a snap! Do I think you should grab this adventure? Yes! Today,now, and start using one of the most underappreciated types of horrors for your game today. A hearty five out of five. "
A second (much shorter) review was posted on DriveThruRPG by user "Zero C":
"I am vey impressed! I picked this up for a look, even though I haven't played OSR rules since the 1990's. I discovered this 71 page adventure site is well-written, well-formatted, and nicely illustrated."
But don't take Zero C and Needle's words on it - download the Fungus Forest and see for yourself! "Pay what you want" means you are welcome to download for free if you can't contribute anything. I guarantee it is a great value for the money :) Full color cartography, art and layout including "The Ring of the Restless Dead" from cave C13 (pen & ink drawing by yours truly colored in Photoshop):