Dungeonbright

Publisher's blurb:

Dungeonbright is a fantasy rpg toolkit built to accommodate modern osr or “adventure game” play. It's structured to facilitate fast GM adjudication and diegetic mechanics.

Short game even shorter:

Three abilities (Body, Mind, Spirit)
Three "fields" (Combat, Expertise, Magic)
Skill system allows you to skip related tasks
Mechanics to minimize the amount of rolling
Everything is treated as either a check or a save (including combat)
Dungeons are corrupted by mythological, wholly capital-E evil darkness
Any PC can cast spells, which significantly differ from TSR-era magic (including in-fiction rules for "recharging" failed spells, and all spells being directly related to dungeoneering)