2D mode

A screenshot of Egg Rock Zone Act 1, an example of a level using 2D Mode in SRB2.

Two-dimensional mode, generally referred to as 2D mode, is a supplementary level type for SRB2 in which the player is only allowed to move on the X-axis and Z-axis, thus restricting movement to two dimensions. The camera stays approximately 448 fracunits south of the player and will always be pointed directly at the player. The camera behavior can be overridden with the use of a cut-away view, but not a camera scanner. In SRB2, 2D mode is used by Egg Rock Zone Act 1 and Act 2.

2D mode is enabled for a map by adding the keyword 2D to the TypeOfLevel parameter of its level header. It must be combined with a gametype. 2D mode is rarely used with any other gametype than Single Player, and previous attempts of making 2D Match and CTF stages were generally considered to be of bad quality.

Features

The controls differ slightly from 3D mode, particularly for movement: Move Left/Right moves the player to the side, and pressing the Move Backwards button while moving causes the player to go into a spin. The player has a 20% higher jump and can turn quickly to the other direction without backpedaling. Additionally, the player's running speed and (for characters with a thok ability) thokking speed is decreased for better control.

Unlike many other 2D games, SRB2's 2D mode allows for real 3D backgrounds. This effect is commonly used in custom levels. Likewise, while the player itself is not able to move along the Y-axis, special effects that move the player, such as scrollers, pushers, or zoom tubes, can still move the player in any direction in 2D mode. This allows level designers to move the player onto a different plane easily while still retaining two-dimensional controls. However, diagonal springs should not be used for this purpose, as they are imprecise and may cause the player to land slightly off the intended path.

It is possible to switch between 3D and 2D mode midway through a level with the use of linedef type 432. This effect works only in levels that do not have 2D mode enabled from the start, since 2D mode is programmed in a manner that makes it impossible to suddenly switch movement rules. Egg Rock Zone Act 1 and Act 2 feature several 2D sections that make use of this effect.