Watch Dogs 2’ s upgrade system lies in the Research app on Holloway’s phone, where new skills can be bought using Research Points accrued as your follower count passes certain milestones. But once you reach the upper tiers of each upgrade category you’ll also need Key Data, a series of pickups hidden in devious corners of the Bay Area. Some require thoughtful platforming; others a Pipe Mania- style puzzle to shut down a security system. Others insist on an often punishingly difficult infiltration of a highly fortified outpost – after a few fruitless hours, we accepted that we won’t be increasing our IED carry capacity any time soon. Still, we appreciate the attempt to bring the skill tree into the world itself, rather than have it be an arbitrary measure of progress through the game.