We were sitting in the highest spot, so we could barely see any of the game.
Literal
We [topic-は] most high place [at-に] was-sitting [because-ので], almost game [object-を] not-could-see [explanatory-んだ].
A compound sentence with explicit cause (ので) and consequence (negative potential見れる). ほとんど ('almost, nearly') paired with negative = 'barely' or 'hardly any.' 見れる is the newer colloquial potential of 見る — traditional form is 見られる, but the らぬき potential is now widely accepted in casual speech.