Ori’s powers are supplemented by a series of upgrades, which are organised not so much in a skill tree as three distinct branches whose nodes are activated with experience points gained from collectable orbs and defeated enemies. You can boost Ori’s energy meter to conjure checkpoints more regularly, for example, or gain extra health each time one is placed. You’d expect the difficulty curve to ease off a little for the most thorough explorers, but an expanded life bar means little when the number of one-hit-kill hazards ramps up markedly. With later foes requiring more firepower to defeat as well, you’ll have to backtrack quite some distance to feel empowered. Still, at least navigation is much quicker once you’ve unlocked Ori’s charged leap and triple-jump abilities.