Various types of obstacles can make gameplay more diverse. This is a good way to increase the difficulty of a game process as well. They may appear in a game one-by-one with the increase in the player's abilities. A situation in which a game is trying to correspond to players who become more trained from level to level is known as negative feedback . The term means that new rules, features, opponents, game speed, and other factors of the gameplay are trying to grade players' statuses forcing them to evolve more. Because of the negative feedback paradigm, the next game levels are always more complicated than their predecessors; otherwise players can loose their motivation and interest because they always need a challenge. There is also such a thing as positive feedback ; as you might guess, it describes situations when gameplay becomes easier for players. Usually, such mechanics are a part of dynamic systems helping players to escape contexts when they are stuck in games. For example, if a player cannot defeat an enemy for a long time, a game can simplify the AI of the enemies and their fire accuracy, or some hints or solutions can be displayed. Positive feedback is quite important because in many cases players drop games because they do not see any ways to resolve problematic gameplay situations. Beside the positive feedback implemented in games directly, there can be so called offline positive feedback —some solutions and walkthroughs published on the Internet (for instance, on the developer's website or YouTube channel).
Obstacles are tiles with special properties that influence the behavior of the array. Some examples:
- Rock: This is a tile painted in black or dark gray. It cannot be eliminated from the array as it is a monolithic structure that does not participate in matching calculations. Being accidentally assembled in long sequences, like in walls, rocks can be very obstructive of player's actions.
- Brick: This is a destructible version of the rock; the tile is painted gray or light gray. It can be eliminated, and the conditions depend on the game type. In the Shooter mode, the player needs to shoot this tile several times. In other modes of the game, it may disappear after a specific period of time.
- Empty: This is one of the most harmless obstacles—simply an empty tile colored white. Sometimes it can impede the assembling of tile sequences, but it can also be easily defeated when a tile is inserted into its position after a recalculation of the array.
- Frozen: This is an ordinary color tile that is bewitched and has lost some of its properties. Such a tile is less saturated, so it can easily be recognized on the screen. As soon as the tile is frozen, it cannot take part in matching. It is ignored by the roll call function and is only marked as semi-frozen but does not give any points. It can be thawed out and can become a normal tile. The tile only needs to get a specific number of semi-frozen marks. You can decide how many attempts it would take.
- Chameleon: This is another bewitched color tile, but in this case, it cannot be uncharmed so it exhibits strange behavior all through the game. The main feature of the Chameleon is changeability of its color; the tile holds one color only for a short period of time, after which the color changes randomly. Such tiles are visually expressed as slowly pulsing squares; the pulsation becomes faster right before the transformation. The Chameleon it pretty harmless, but it can confuse the player by throwing a wrench in his strategic plans.
The following figure shows the various obstacles we just covered:
It is important to note that some obstacles can have a particular affect on some game modes. For instance, in the Scroll mode, Rocks and Bricks can prevent a row from being scrolled. If one of their kind is stretched against the edge of screen, the player has to scroll down when such a tile appears. The Brick may be broken by several hits against the screen frame. Frozen tiles in turn require few taps to be thawed out in Moving columns and Tile-o-fall modes.