2D platformer or 3D platformer? Many will have a definitive preference to that decades-old question – but Screenbound dares to ask: why not both?

It’s a simple enough pitch, but playing the game’s GDC demo shows you how complex a challenge this will have been for developer Cresent Moon Games. Screenbound begins when your character discovers a mysterious device known as the “Qboy”. Seemingly left behind by their mom, it’s affixed with a post-it note reading “Find Me”. Turning it on, they’re transported to an archetypal game world; floating islands, chiptune soundtrack, coins to collect – the works.

Except, as the player, you navigate this world in both 2D and 3D simultaneously. From a first-person perspective, you’ll see the full 3D world arrayed around you, but you’re always holding the Qboy at the bottom of the screen, showing the same level as if it was a retro 2D platformer (well, 2.5D if we’re being picky).

As the demo begins, you quickly get a handle on things – making your way around a colourful 3D world, avoiding obstacles, platforming, battling enemies and exploring, all while seeing the secrets and storytelling this world has to offer.

You’ll never be lost though, as your 2D view gives you the clearest sense of your objective, and key collectibles or pathways that might not be visible from your current 3D viewpoint become far clearer in a flattened-down world.

Where it starts to get really tricky is when you need to start using both in tandem. Some items might only be visible in the 2D version of the world, while some obstacles might only be visible in 3D (or vice versa) – you’re going to quickly need to start flicking your eyes, and your attention, between both as often as you can. For some puzzles, you’ll need to use both perspectives – you might find yourself blocked from progressing in the 3D world, only for the solution to be in 2D. This is made more engaging by using your trusty Qboy to help merge both worlds in a “Q-view” mode, showing the secrets of the 2D world in 3D to help you solve challenges.

Sometimes the game takes you entirely into 2D. Behind doors and inside consoles, you’ll find platforming sections that can net you extra coins, and unlock the way forward in the 3D world, while also hiding some of the Qube collectibles you need to unlock bonus levels. There are even secret exits that can lead you to entirely new parts of the level.

Within just the first world of the game, new weapons, block types, enemies and more are introduced to one or both of your viewpoints, asking you to learn new rules on the fly.

Even in these earliest stages of the game, the possibilities for how far Cresent Moon Games could take this are dizzying – not least because a trailer after the demo concludes teases that this is just “Cartridge 1”. As we unlock new cartridges, it seems Screenbound itself will begin to morph into different styles – adding new ways to play while paying homage to the 2D titles that inspired it.

Combining perspectives is one thing – and there’s more than enough in here already to imagine a game’s worth of mind-melting puzzle-platforming – but combining entire genres on top of that might make Screenbound even more impressive.