Platformers started out in 8 bit 2D games. Graphics were flat and animation was simple. The limitations of video games meant all games were 2D up until the late 1990s. Even with the advent of 3D, the platformer remained mostly fixed to a single axis. Modern 2D games tend to be in 3D but with a restricted player movement in a two dimensional plane, giving the feel of something solid and real, but with the gameplay of traditional platformers.
Fixed camera. Room escape.
This is the style prominent in early 80s games such as Sir Lancelot and Jet Set Willy. You generally have to navigate a room to reach a door at the top right of the screen. Often features puzzle elements such as collecting keys or pushing blocks. Enemies are characters you should not touch and room based traps such as spikes, moving platforms and walls.
Side scrolling worlds.
The style prominent in the 90s with games like Super Mario Bros. Movement is generally left to right and sometimes up and down. The goal is to get to the end of the level without using up your lives. Often includes a collecting mechanic. Enemies can be attacked by the player (often by jumping on them).
This style creates the illusion of 3D within a 2D space. Early examples include Knight Lore and Ant Attack. Games tend to be more puzzle based rather than strictly platforming. Enemies are generally ones that cannot be touched, attacks by the player are usually projectile based.
The game is 2D but has a sense of depth due to the parallax effect, where layers move at different speeds, have different focus and use colour to convey distance. Many modern platformers that regard themselves as 2D will use this effect. Generally used in left to right sidescrollers like Limbo.
This is where 3D models are used in a 2D gamespace or 2D models fake a 3D look. The former is the more frequently made, with games like Little Big Planet and Unravel.
3D (Three dimensional)
Many 2D titles evolved into 3D platformers, where the player is not confined to one axis. Titles include Super Mario 64 and Sonic the Hedgehog. The goal is essentially the same as before, navigate to the end of a level where there will be some sort of door or flag. These games tend to have more of a story, and often feature the addition of cut scenes.
These platformers generally involve a moving environment where the player has to avoid oncoming obstacles. The idea is to stay alive as long as possible. These games are often procedurally generated, and as the name suggests the level never ends, though some do have rest points. These games are normally played on mobile devices. Temple run is the most famous example, along with Flappy Bird.
Although most platformers have some element of puzzle to them. Puzzle Platformers such as Limbo and Unravel specifically require you to work out how to proceed through the level by solving puzzles rather than just relying on platforming skills of timing and speed.
The player controls either the marble or the environment (tilting the floor) to get the marble through a maze. The most successful of these was Marble Madness.
Game mechanics and features that are prominent
Either left and right up and down or rotating, these are a main feature of platformers where the player has to time jumps as to not fall in to a pit, water, abyss or whatever hazard is below.
Whether these are coming out of the walls like in Indiana Jones, coming down from the ceiling, like in Indiana Jones, or found at the bottom of a pit like …. well, you get the idea, these little hazards are a very popular way of killing your player.
Jumping from wall to wall to traverse a chimney like structure is a very popular way of getting your player higher in your map.
Quickly pressing the jump button while in the air allows your player to get across gaps they previously could not do. For this reason the ability to double jump is normally added as a player reward for completing earlier levels.
Similar to the double jump, a press of a button while in the air and the player dashes forward, allowing them to get across wide gaps.
Some platformers require you to collect objects in order to complete the level, others just give you more points or in-game currency. Collectables can also prolong gameplay where the player can go back to a level after finishing it and collect hidden objects which were not on the main path as a secondary goal.
This can be an object in the level or an ability your player possesses. Ropes, chains, vines can all act to get your player higher in your map with climbing, or swing them across big gaps.
Also pull blocks. These are obstacles or aids in the environment that the player can move in order to unblock doors or get to higher places.
These games require you to get through the level as quickly as possible for a higher score. You normally have infinite lives, but you will return to the start or a checkpoint at death which affects your time.
As the player progresses through the level they may activate checkpoints where they will respawn if they die. These are normally placed before or after a particularly difficult section.
A timed hazard is when the same sequence plays out that the player can learn how to avoid. Raising and lowering walls are a good example of this. A well timed jump, pause or shot is normally the solution to these. Changes in the sequence keeps the player on their toes.
Character enemies in platformers are generally repeated throughout the level and normally have a particular vulnerability that allows the player to get passed them. Some follow a set pattern of movement that you can exploit, some can be killed with weaponry or a jump on the head.
Can you make these in Dreams?
Yes, in fact a platformer is probably one of the more easy genres to create. Media Molecule provided a kit of platforming pieces from their level Dreamiverse Dash to give you a start. You can make 3D, 2.5D and 2D platformers. You can even simulate an 8 bit look.