1. Lens of Problem Solving (6)

The game requires players to hit all the pigs in every stage with the minimum number of birds, with a specified maximum number of birds.

Players may have different skill levels which may cause novices at judging the expected target to experience difficulties in passing each stage.

Each type of bird is given a different special ability that can help get through certain obstacles. The order of the bird is also pre-determined that require players to solve them in a limited number of ways. The terrain changes so that new obstacles are introduced that require players to use different strategies to overcome, such as meteorites that block the path, lasers that knock the birds from their path, etc.

2. Lens of Flow (18)

The game has clear goals where player have to hit all the pigs with the specified number of birds or they would be considered to fail the stage and forced to restart. High scores are notified to the players so players know that they have to get a high score.

The goals of the players are the same goal Rovio intended. There is no other way to clear a stage until all the pigs are hit. While players can choose to give up the goal of obtaining a high score, this goal is not essential.

Bonus stages can be unlocked by hitting special eggs placed in some stages. To hit these eggs, players may overuse birds so that they do not have enough to hit all the pigs, hence having to restart. However, the number of these eggs is minimal at the cost of not being tied into the game goal, since there is no significant advantage to clearing these bonus stages.

The challenges presented to the players are in different forms for different ‘worlds’, such as laser, meteorites, or gravity. However, they are not necessarily increasing difficult.

Once players learn to control the direction and speed of the birds from the catapult, the only skill required is the time of executing the special ability. These skills do not take many tries to learn, hence there is little improvement after the first few stages. To get a perfect score however, precise execution is required, which encourages players who are goal-centric to work on improving their skill.

3. Lens of Skills vs. Chance (34)

Players are judged initially by skill for those stages that are relatively straightforward, but as stages become more complicated, players need to take risks to get perfect scores.

This dependency on chance reinforces the idea that the game is more casual than serious.

The game is balanced between requiring skill and strategy to hit the pigs at the right instance to clear a stage, but also requiring risk taking to minimize the number of birds used, hence obtaining a higher score.

4. Lens of Parallelism (50)

Players are required to solve each stage before proceeding to the next. This creates bottlenecks. Players can play bonus stages but them while helping to eliminate these bottlenecks but also cause the player to be distracted from the main goal.

Parallel challenges such as bonus stages have the same gameplay; hence there is a lack of diversity and challenges.

Since the game does not become increasing become more challenging, making progress on parallel challenges has minimal impact on solving the main play. However, since the main play and the parallel challenges have similar gameplay, it may help to improve the player’s skill.

5. Lens of Control (53)

When players use the interface, it does what they expected in that players pull back on the catapult and expect to see the birds fly. It may not fly exactly according to the player’s expectation due to challenges of the game including ‘gravity’ that alters the path of the bird.

The interface is easy to master; players just need to touch to pull and release.

Players have a strong influence over the outcome of the game since the birds fly in the direction according to their plan, even with obstacles such as gravity, once they expect the gravitational pull, they can adjust the speed and direction of the bird.

Since players are in control of the birds, hence players feel powerful. While players can be made more powerful, this will reduce the challenge of the game, hence a balance needs to be struck.

Game’s web site: http://www.rovio.com/

Game YouTube link: http://www.youtube.com/watch?v=mY29T3Sqz30