Level Design 101/Single Player

In Single Player maps, the designer's main goal is to challenge the player with unique and interesting obstacles while they are trying to the reach the exit. While the player generally follows a more or less linear path to the finish, this path is usually broken into multiple paths throughout the level to add more content to the stage and encourage repeated playthroughs. Another important way to increase a level's replay value is to scatter secret items throughout the map that the player can search for. Most Single Player stages also support Coop and Race, although sometimes this is unfeasible when the map isn't designed to be played by multiple players at once.

General

• Make sure there are plenty of secrets in your map. Reward the player for going out of their way with extra lives and power-ups. Place really useful items in hard to reach areas, and hide stuff just out of the player's sight. Having tons of stuff to find encourages the player to go looking for it, and that makes the stage have a lot more replay value.

• Make sure your secrets are useful to the player. Some items, such emerald tokens, extra lives or Super Ring Monitors, are always useful. Others, however, are more powerful in some situations than in others, and they should be placed accordingly. For example, placing an Invincibility Monitor in an area without hazards or an Elemental Shield in a level without environmental threats will make the player feel cheated, whereas placing an Whirlwind Shield near a secret area that can only be accessed with the additional double jump can add further replay value and makes the player feel clever for figuring out how to access it.

• Don't place score monitors directly on a map. Score monitors are only meant to replace extra life monitors in Record Attack. In a normal game, score has little relevance, so score monitors are near-useless as power-ups.

• Don't combine shield types that don't fit together. SRB2's regular levels only use the five main shields: Attraction, Force, Armageddon, Whirlwind, and Elemental. They are designed to complement each other – for each shield, there are situations where the player would prefer it over all others. For example, Elemental is the most desirable shield in stages with elemental hazards, whereas Attraction is the most desirable when collecting rings in Record Attack. The Pity Shield was designed for Match, where it is given directly to weaker players but never spawns out of monitors. While there are valid ways to use it in Single Player maps, for example as the only available shield type on a map, don't simply use it in addition to the other shields. Because it is strictly weaker than all the others, the player will always want to replace it. Likewise, be careful when combining the S3&K shields with the main shields. For example, if your map uses the Lightning Shield, it should probably not use Whirlwind and Attraction, since their features overlap.

• Use Star Posts a lot. There should be one before and after any difficult area. Getting past a difficult part only to have to do it over again after dying in the next room is highly frustrating. Also, placing a Star Post with rings in front of it right at the point where paths merge is a very effective method of making sure the player doesn't accidentally go backwards down the path they didn't take.

• Make the stage become more difficult as it progresses. The player should be eased into the level with small and simple challenges and then increase the difficulty step by step. Introduce gimmicks in an easy and safe scenario before using them in more complex ways. If the beginning is too challenging, then the player might be frustrated and quit, and if the difficulty never increases, the player might feel bored. However, bear in mind that the difficulty also depends on your intent on how hard the stage should be. Not every stage needs to be difficult, but a noticeable difficulty curve is nice if the stage is intended to be challenging.

Obstacles and gimmicks

The objective of Single Player stages is to get to the exit and avoid obstacles along the way. Creatively used obstacles can be used as gimmicks that make your stage unique. Providing enjoyable challenges that the player hasn't seen before is the key to making an enjoyable stage.

• Obstacles should fit the theme of your stage. For example, using lasers in an nature-themed environment will look strange. The player should have the feeling that any obstacles make sense in the environment they are provided in. Often, the visual implementation can help to fit obstacles into a stage.

• Make sure the player can't skip obstacles. If the player has to cross a gap via platforming, make sure it is long enough to make spindash-thokking useless. If an obstacle can be too easily avoided as Knuckles by simply climbing, give the walls the Not Climbable flag, or put a damaging object onto them like in Egg Rock Zone Act 1. Don't go overboard though; Knuckles and Tails should still be able to use their abilities to their advantage.

• Gimmicks should involve gameplay. Making the player interact with their environment in some unique way is what makes a stage interesting and fun. A gimmick that removes control from the player or doesn't force interaction is boring in most cases. For example, don't use waterslides just for the sake of having them. If you use them, make sure the player has to do something while being carried. This is especially true of zoom tubes. It's impossible for a player to move while in a zoom tube, and therefore they should be used sparingly and never as a substitute for actual gameplay.

• Don't let your gimmicks get stale. It is perfectly fine, though not required, to use some gimmicks more than once per level, as it gives the stage a sense of familiarity. But no matter how clever and inventive a gimmick is, players will get sick of it if the gimmick keeps repeating itself or goes on too long. If you use a gimmick multiple times, it should constantly reinvent itself and/or combine with other gimmicks in new ways. Ideally, the difficulty and complexity of the gimmick should gradually increase. The intermittent gravity-flipping machines in ERZ2 are a good example of this.

• Mazes are bad. They confuse the player because they don't know where to go. Nothing is more frustrating than having no idea where you're supposed to go. Every path that the player is able to take should lead somewhere and not into a dead end.

• Don't overuse buttons. Occasional use for a secret or other trick is okay, but don't base your stage around pressing buttons to open the exit. If you need the player to trigger a certain event, try to find a creative way of triggering it, like the button that is submerged in goo near the end of Techno Hill Zone Act 2.

Multiple paths

Have the stage split up and rejoin in different areas. When stages have multiple ways to go through, it adds replay value and allows players to try to find the optimal way to go through quickly.

• Make sure the player knows where to go. Make clear which way goes forward and which backward, especially where the paths come together. You don't want the player going backwards on the path they didn't take. There are several ways to do this, like having the paths come together at an angle that doesn't allow you to see the other, making it impossible to enter a path from the wrong end, or placing a trail of rings that leads in the right direction. If possible, don't use arrows to show where the player has to go. An intuitive layout is always more effective.

• Length and difficulty of different paths should be balanced. Neither path should be much longer or harder than the other. If one path is harder than the other, it should be shorter, and vice versa. The second path split in Techno Hill Zone Act 2 is a good example of this. The player has the choice between the easier, but time-consuming lower path, and the faster but risky Deton path. In previous versions of SRB2, the Deton path used to be both longer and harder, which resulted in it almost never being used.

• Separate paths should have separate content. One path should be different from the other, containing different challenges and different gimmicks. A second path that features same or similar gameplay to the first one is boring. If you want to, you can focus on different gameplay mechanics and gimmicks on each path. In this case, it is a good idea to introduce the player to the style of a path as long as they can still take the other one. For example, a path focused on puzzles should begin with a puzzle, so that the player can choose to take the other path if they don't solve the first one.

• Make sure the player is introduced to important gimmicks no matter which path they take. As long as a gimmick is restricted to a certain path, this is not important. However, if you introduce a new gimmick on a path that can be avoided and the gimmick is used in a different part of the level later on, the player may not have seen it before. In this case, you should either make the second instance of the gimmick intuitive enough that the player will understand what to do anyway, or you should move the introduction of the gimmick to a part of the level that is mandatory.

• Path splits don't need to be left-right decisions. While it is okay to split a path by simply providing two different doors to go through, this might be undesirable because it forces the player to make an immediate decision. There are other ways to split a path, such as providing two different options to cross a room that ultimately lead to different exits, or having the player fall down to a lower path in case they miss a crucial jump on the higher path. Additionally, it is possible to split a path into more than two components, split already split paths even further, and having different paths meet up more than once. As long as the level layout is intuitive to the player, there are no limits.

• Don't make too many parts of the level mandatory. This can seriously hurt the player's desire to play the level multiple times. If possible, provide alternate paths for all parts of the level except for the very beginning, the very end, and short sections between path splits. Leave the player with a choice as often as possible.

• Use caution with shortcuts. If a shortcut is too easy to access, the main path will almost never get used. A good shortcut will save a considerable amount of time, but will provide the player with an extra challenge.

2D Single Player

You must make sure the player knows what's ahead of them at all times. Since SRB2's 2D mode allows Sonic to go faster relative to the camera distance than in the classic Sonic games, it's easy to enter a situation where the player can't see as far ahead as they need to.

• Stop the player when a hazard is coming up. Force the player to stop dead before they make crucial platforming jumps or avoid hazards in the level; otherwise, the player will miss the jumps and/or plunge into the hazards before they even see them, possibly resulting in their death. The same goes for enemy placement.

• Make sure that sections where the player can run at full speed have no danger. Sonic moves too fast for the camera to keep up, so putting a hazard in such a section is simply unfair; the player couldn't even see it.

• Leave room for the camera. It is always about 448 fracunits away from the player, and if the player hugs the thok barrier or another long wall that long, the camera will act erratically. Make sure the walls never come in contact with the camera, or otherwise block the camera.

• Don't use two-sided linedefs longer than approximately 10000 fracunits. It causes the hall of mirrors glitch to occur. If you have a room that long (which you probably will), split the linedefs to avoid.

• 2D-3D transitions should be pulled off properly. If the player is able to walk during the transition, their controls will suddenly swap and they will finding themselves suddenly walking to the left instead of forward. To avoid this, take away the control from the player, for example via a teleport or a zoom tube.

• Make use of the third dimension. SRB2 allows for scenery in the background, even in 2D levels. This can make a stage visually more attractive and interesting.