Although you could call Inside a puzzle-platformer, it’s really more of a horror-tinged thriller. Mystery, dark humor, a sinister setting—it’s all here.

Tension too. You play a young boy navigating a perilous world, and carelessness inevitably ends in grim, sudden death. To offer some respite, there are smart puzzles to solve here, but a sense of impending doom pervades.

Arnt Jensen, founder of developer Playdead, describes Inside as “an evolution” of his company’s debut game, Limbo. You can think of Inside as “more than a follow-up” but not quite a sequel, he says. “The games share the same creative philosophy.”

While Inside shares Limbo’s mechanics and atmosphere, the scale of the newer game—first created for consoles—is far greater.

“During the production of Inside, Playdead grew to twice the size it had on Limbo, and the budget quadrupled,” Jensen says. “Everything, including sound, gameplay, rendering, and graphics, was much more ambitious and complex.”

That vision was not compromised when it came to the arrival of Inside on the App Store. From a technical standpoint, this is the same game that arrived on PS4, Xbox, and PC but with controls reworked for iPhone and iPad.

“The public might not realize how difficult it is to fit a console game into a handheld device,” continues Jensen. “We have been working extremely hard to make sure that people on iOS get the best possible experience.”

Having garnered over 100 gaming awards and the accolades of critics, Inside remains one of the most gripping games to arrive on any platform in the past few years; with its App Store debut, more surely await.