I played Last Oath and I feel I could play it again and again.

Its OSR-ish rule system, which could easily be used to play regular group or solo campaigns, can be adapted to the way you would like to play this gamebook — with more or less lethality, with or without classes, etc. —, due to the many options it provides.

It comes with a map, which you may or may not use (I did) to guide yourself in this dungeon, and both the way it describes its rooms and the way it lets you explore them allow for different playstyles.

Its thematic is fantastic and mysterious and made me want to keep adventuring in this post-apocalyptic fantasy world with the character I could finish the dungeon with, Zarathus, the Sage. The dungeon feels alive and it is very well connected to the story and even to the system itself (especially to the magic items' mechanics).

Finally, the book is illustrated by the author himself, and it seems to me that the art can communicate the tone and the weirdness of the setting. I wish I could draw for my games too (and I wish we could see more of this, rather than so much artificially produced imagery).

TL;DR: it's good, you should get it!