"The best designers marry function with form to create intuitive experiences that we understand immediately… the ability to instill a sense of instant familiarity." - John Maeda, Laws of Simplicity
Signs in games have the sole purpose of indicating to the player what the function of a specific element in the game world, is so as to prepare them for the result of their interaction with it. An enemy covered in thorns, for example, is likely to be harmful upon physical contact, which should lead the player to the realization that hand-to-hand combat is out of the question. Through one simple aesthetic choice on the part of the designer, the player now has an inherent understanding of the abilities the creature possesses, and has the logical tools to overcome the threat.
Signs need to be self-explanatory, as well as unambiguous; if the enemy is covered in dull-tipped spikes, while they can clearly be seen as spikes, they could be mistaken as blunt and therefore harmless; designers must make an effort to keep signs simple, clear and perceptible, so as to have the highest chances of immediate understanding from the player.
Signs can come in the form of sounds, special effects, textures, animations, vibrations, and even character design; almost every aspect of a game should be used for the sake of creating clear signs all throughout the game world.
Feedback is the information given to a player after he has done something in the game world, such as a vibration upon crashing his car into a building, or the simultaneous explosion from the front end of the vehicle and the accompanying sound effect.
Feedback should come from everything in the game, from player initiated character actions to gameplay element reactions, and even heads up displays. The best feedback is immediate, so as to create a clear and inherent correlation between the action or stimulus and the feedback of the reaction.
With this unambiguous association, the player can begin to understand the game environment, and better execute actions intentionally and in a correct and coherent manner.
While many different sound effects can be played at the same time, such as the background track, ambient sounds (signs) emanating from the nearby gameplay elements and the feedback from the player's last input, it is necessary to keep all these layers of feedback locally organized by balancing the volume of each sound layer to increase the impact of the feedback and not mask it by other environmental or ambient sounds. This is true of special effects and animation as well; all feedback on screen should maintain a good balance to maximize clarity and readability.
Distinct colors form recognition and patterns; green elements become friendly with a similar purpose, as can be seen in the adjacent image. All platforms share a yellow-green color across all the different worlds, and the bumper objects, also similar in shape, have the same color palette to categorize them with the safety implied with the other platforms.
Also, by keeping colors rare, they help to emphasize the significance of the specific object, as well as establish a clear contrast between itself and the surrounding environment. This principle holds quite true to the color composition of the playable characters as well; it is important that a game's characters not blend into the environment too well, otherwise they might be hard to keep track of.
Not only color, but size can have a large influence on the clarity of a gameplay element; if an enemy is roughly the same scale as the player character, it is quite easily understood that they are of equal strength, and as such the player should be able to dispose of them with little effort.
The flower bumper in Rayman Origins has two varieties, one default scale and one which is twice as large, as an indication of the fact that the supersized bumper has twice the launching power of the default-scaled one. Simply by making the asset larger, it becomes a clear sign for the player that this will not function in exactly the same manner as the smaller bumpers the player might have previously encountered.
One principle that was well-implemented in Rayman Origins is the use of a strong recognizable silhouette for clear indication of danger. As can be seen by the adjacent image, all of the dangerous gameplay elements from all of the varied worlds in the game share a similar spiky silhouette as an indication of the inherent danger of the object.
While these objects do not share a similar color palette to indicate their inherent danger, the silhouette alone serves as a clear enough sign for universal understanding. By combining a strong silhouette with color and scaling, a gameplay element can be extremely apparent, readable and clear almost immediately.
"Too many games offer the same gameplay over and over. If you want to make a joyous game, fill it chock-full of wondrous things to see and do" - Ernest Adams, The Designers' Notebook, October 2010
Variety is essential for breaking the repetitive nature of a core gameplay style, so as to keep the experience fresh and exciting for the player, as well as providing them with an experience which might require them to rethink their gameplay strategy to cope with the new conditions.
In rational game design, the best way to implement variety in a game is to approach it in a subtractive way; rather than adding new mechanics and new learning, remove half of the mechanics the player has become comforted by over the course of the game so as to force them to learn to cope without them.
"Simplicity is about subtracting the obvious and adding the meaningful" - John Maeda, Laws of Simplicity
Variety in gameplay should change the player's rhythm significantly; the way they approach a challenge normally might not be an option in the current challenge, so they must learn to play in a different way if they mean to complete the sequence. Input frequency and types of inputs are key ingredients to creating good variety in level design; by forcing a slower rhythm, the sequence can force an otherwise speedy player to take it slow for a change, and give him a new sensation that he otherwise would never impose on himself.
One example of this is the level "Skyward Sonata" in Rayman Origins, which has the player constantly running on top of a short snake-like flute that is flying through the air, which forcibly scrolls the camera forward outside of the player's control. The constraint of not only having a small safe area to stand on paired with a constantly scrolling camera adds a lot to a player's anxiety level independent from the actual gameplay challenges posed in the level itself.
Because of this, I had to compensate and make the challenges quite simple, almost as simple as the challenges found in the second or third level of the game, but purely because the player is out of their comfort zone and constantly moving, the simplicity of the challenges balance it out and keep the level achievable but memorable.
These moments of variety in a game must be tweaked in such a way as to not disrupt the macro flow of the game, however, as a drastic change in gameplay can be confusing for a player, and by making the level too challenging as well can throw off the delicate balance of the macro flow.
Variety also comes in the form of different challenges displayed in a level, each with their own distinct risk and reward to help the player make a conscious decision on how to proceed. A Skull Coin can be placed on the upper path surrounded by spikes, while on the lower path the player is presented with a King Lum sequence.
In essence, both paths can provide the player with the same physical reward (a Skull Coin is worth 25 Lums), but the clear difference in presentation the two paths makes the experience all the more unique. What is also interesting to note is that even if the player never ventures onto a certain path in the course of their play through, simply by catching the existence of the path in the corner of their eye provides a sense of depth, coherency and expansiveness to the game universe which only further facilitates the sense of immersion.
Large contrast makes for highly memorable moments; the more extreme the difference of the in game conditions from the norm, the more memorable the variation will be. In the boss fight "My Heartburn's for You", the player is enclosed inside of a giant dragon's stomach and pursued by long flame trails. This situation removes the ability to do anything else, which results in clear emphasis of the importance of the wall-run mechanic and induces a stronger appreciation for it that the player might not have previously felt.
While one must be cautious not to revisit the same unique game format too often with the risk of removing the uniqueness and memorability of the previous instances, repeating combinations and variations can provide the player with a feeling of understanding and recognition, meaning that their second chance at a specific level format can give them a feeling of superiority that had been taken away from them in the first instance.