2D Platformer Perspective

In designing my game, I’ve been thinking about perspective. I’m trying to make a 2D platformer, but despite the name not all 2D games have a purely two-dimensional art style.

For the most part, existing 2D games have two-dimensional art. Most of the classics are completely two-dimensional in both gameplay and art: Super Mario games on NES and SNES, the first few Sonic games, Donkey Kong Country, to name a few.

Exceptions to this are games with two-dimensional art but some depth to the gameplay River City Ransom and Streets of Rage, and games with two-dimensional gameplay but 3D art like Shadow Complex and Rochard.

What do I mean by perspective?

Returning to fully two-dimensional games, the important thing to note is that unlike 3D games, they are not constrained by the conventions of 3D camera projections, and are free to fake perspective how they choose. So the word perspective in 2D games is a little vague, but put simply, in this case I use it to talk about the angle between virtual camera and the world. Based on this I’ve split perspectives into two very general categories.

Completely Side-on

The vast majority of early platforming games are in this genre. On Nintendo consoles alone there are the Super Mario Bros, Metroid and Castlevania series. More recently Fez, Spelunky, Super Meat Boy and Dustforce have all used this projection.

The defining feature of this group is that the platforms that the player stands on have no depth at all. There are pixels below the player supporting them, but little or no foreground or background on that layer. There can be parallax layers behind and in front of the character to add depth, but the “camera” is effectively 90 degrees to the scene.

▲ Clockwise from top: Super Mario World, Metroid, Fez.

This is all very fascinating, but effect does this art style have on gameplay and expressivity?

  • Makes for pixel-perfect platforming. There is no ambiguity about where the player will land.
  • Unambiguity makes the controls feel “tight” and responsive.
  • Less space to add art details to terrain. Artists have to use background layers behind and under the character to add detail.
  • Looks more ‘retro’. Either from the years of retro video games we grew up with or unrealistic projection, despite any art style I feel side-on platformers look retro.

Varying levels of depth

This is a much more nebulous and vaguely defined group than the previous one. In essence it contains all games that aren’t completely side-on. This is far from an exhaustive list, but to give a few examples: Donkey Kong Country, Aladdin, Rayman Origins, Dust: An Elysian Tail.

Unless the game features a 3D engine, there is no real camera and no real projection. Any sense of perspective must be faked by the art style. The z-depth of platforms is shown through a texture that differentiates it from the front and back of the platform. In Aladdin it’s flat sand with a highlighted front edge, compared to repeating sand dunes. In Rayman it is much more subtle, but the layer containing the player is lighter than the rest.

▲ Aladdin's floors have depth, showing some of the ground.

Some games like Donkey Kong vary this z-space, giving the appearance of widening and narrowing platforms.

▲ Donkey Kong Country's ground-depth varies.

However in areas that require more precise platforming, the z-space is reduced, as shown in Donkey Kong and Rayman. Compare the space that Rayman is standing on to the depth of the floating platform.

▲ Rayman

So what does this kind of projection give rise to?

  • More space for artistic expression – can add ground details
  • Looser platforming controls – The exact place where the player will make contact with the ground is made less clear by the amount of foreground and background detail to each platform.
  • More realistic appearance by giving depth to the scene through broadening the platforms on which the player stands.

Which to use?

It depends on the effect you are trying to achieve. If your game’s primary mechanic is not platforming, and you want some more room for artistic expression and possibly realism, then go for the latter group. On the other hand if you are trying to create a “tight” platformer, a completely orthographic perspective could help.