A preview of the game here

This project is a simple recreation of Jetpack Joyride.

Theme: the game is inspired by Halfbricks Studio's Jetpack Joyride game. All of the images were taken from the game itself. The player is a man using his jetpack to avoid obstacles and obtain coins.

Customization:

1. Movement: Instead of being able to move in all four directions, the player can only move upwards. This is reasonable since the main character is using a jetpack and it can only fire upwards. However, gravitational force will naturally pull him down.

2. Obstacles: The obstacles have different speed. The laser is a static object so it "shifts" left in the same pace as the game. The rocket is moving towards the player, so it "shifts" faster than the laser. As a result, rockets will instantly kill you after collision, while colliding with lasers is less lethal.

3. "Recovery time": this is the period where the player is flickering. When the player is in recovery, he is immune to collision with any obstacles (he can still collect coins and tokens). The recovery time usually takes place after collision or special power for the player to adapt to the change.

4. Special Power: the token gives you special power. "Invincibility" will fast forward you in the game, make you immune to collision but still have the ability to collect coins. "Lil Stomper" gives you an extra armor. You will not die from rockets, however, you only lose the armor. The armor also provides you with lives against the laser.

5. Difficulty: The game will VERY SLIGHTLY increase the difficulty as time passes (the likelihood of spawning object increases). After you reach halfway (score = 0.5 * winningScore), you will temporarily face only rockets (at a higher spawn rate) and the speed of the game slightly increases. After you reach three-forth of the game, lasers will be brought back to the game, but rockets are still spawned at a high rate.

6. Winning/Losing Condition: reach 100 points (to win) or lives = 0 or collide with rockets (to lose)

How did the extra features were implemented:

1. Gravity:

• constant: (boolean) activateGravity: indicate when to activate gravity (int) STARTING_GRAVITY: the default speed of falling (int) gravityFactor: speed of falling (will be adjusted during the game) (int) DEFAULT_MSLASTSPACE, msLastSpace: keep track of the last instance the player hits space to change the gravityFactor accordingly
• method: gravity(); handleKeyPressed();

2. Different Speed:

• constant: (int) ROCKETSPEEDRATIO: how faster the rocket moves in respect to other objects (boolean) populate: indicate when to populate right edge
• method: scrollLeft(), checkPopulate(), populateRightEdge() --> the different speed creates a new problem when populating right edge because they are scrolled left differently

3. Spawn Object:

• constant: (int) coinSpawn, laserSpawn, rocketSpawn, tokenSpawn, maxToken (double) probabilityGem, probabilityPower (int) msLastToken, DEFAULT_MSLASTTOKEN: keep track of the token spawn
• method: getObject()

4. Difficulty:

• constant: (int) DIFFICULTY: affects spawn rate (int) MIN_DIFFICULT: the highest spawn rate in the game (int) rateIncreaseDifficulty: how often difficulty is updated
• method: increaseDifficulty()

5. Special Power & Recovery Time

• constant: (boolean) lilStomper, invincible: to indicate which special power is activated (boolean) shield: recovery time (int) INVINCIBLETIME, startInvincible: keep track of how long the player "invincible" (int) msGamePause: keep track of the small pause when the player gets the special power (int) SHIELDTIME, startShield: keep track of how long the player is "in recovery"
• method: invincible(), handleCollision(), printPlayer()