I'm not talking anything as big as a Fireball or Wish. I mean even something on par with low-level OSR spells or petty magic from Warhammer Fantasy (i.e. Firebolt, Magic Missile, Spider Climb, Web, Fog Cloud, etc.) The stuff in Forbidden Lands is way, way less impressive than even these low-level spells.
And I'm good with them having costs to cast, critical spell failures, etc.
But without this magical basis, I can't run a "typical fantasy" world. Forget about running Isle of Dread or Dark Sun with the magic system in Forbidden Lands.