The document outlines the development process of a 2D space shooter game. It describes how the developer began by designing a player sprite and adding animation and collision detection. They then coded player movement and added boundaries to keep the player on screen. Background scrolling was added along with particle effects for engine thrusters. Enemies were created that move and shoot, and the player can shoot enemies to score points. Later, the developer added a health bar, boss battles, and menus to complete the game.

1. Unit 70 – 2D Game Documentation
I began the project with my initial sprite design which was a basic black and red
ship in a spined, stealth plane look with shading added onto small areas such
as over the cockpit, then I progressed to make gun shapes to add a counter
from the initial shape

2. After making the sprite I added a few small animation frames to add little
moving details such as a trail of fire alternating from the rockets.
After making small details in the animation of the sprite, I created a suitable
collision mask that fit well around my ship and would be accurately responsive
to shots etc.

3. Once I’d made a suitable sprite with a decent collision mask, I begun coding
movement steps onto an empty object with the sprite, which would shift my
ship in different directions using the “WASD” format.
I then moved on to placing my ship into a basic room and testing whether the
controls of the ship worked in relation to the game.

4. After testing my player in the room, I coded movement limits onto my ship
object which would stop my Ship from flying off the screen, which would go
against basic rules of a static side-scrolling shooter.
Once that I had made the basic room with the movement limits, I added a
scrolling background effect which was done by setting the background
horizontal speed to move right to left in a loop.

5. Once I had my scrolling background I moved onto creating an illusion of speed
and dashing with small white lines moving at their own horizontal speed
independently from the background.
I moved onto creating a particle engine system, which would produce moving
and shrinking sprites constantly but in randomized forms in order to make an
illusion of engine movement, after creating a first jet and moving it onto one of
the ships engine parts, I duplicated the coding, but changing the Y-axis to be
inverse to have another jet on my ship.

6. I then moved onto movement and sound of a player shooting a laser, with
the sound effect playing each time the key is pressed, and then I coded a
step event which would destroy the object once it had left the screen,
minimizing lag and bugs in the game.
After I’d set the players details, I moved onto the enemies, how they spawn,
how fast they move, and with my quick scrolling background, I wanted to
make the enemies fast too.

7. Once I’d created my fast paced enemies, I felt it was time to make the
enemies be destroyed by the player collision as well as the bullets the
player shoots, as well as playing a small particle script which would be the
explosion effect left after the ship being destroyed.
I thought this might be useful because it’d make it obvious you destroyed
the enemy, with a very contrasting explosion which is in similar hue to that
of the background, but with black to differentiate from it.

8. To add more challenge to my game, I made the enemies able to shoot
projectiles which would move in the direction of the player, which came
out as planned, aiming straight for the player with bright projectiles which
were useful to have in ramping up the difficulty of the game.
Once it was possible for the enemy to shoot, it made sense to create a shield
which would deplete with each bullet from the enemy making contact with
the players’ collision box.

9. Coding the shield dropping from the enemy collision also made It possible
to insert a deflect frame which would quickly flash red upon contact, once
depleted, the character would be destroyed, activating an explosion
particle effect similar to the enemies but for the player, inverting it and
turning it blue.
Once It was fair for both the enemy and the player to be destroyed, it was
about time to implement a score system which would activate upon an
enemy instance becoming destroyed.

10. In order to ramp up the difficulty of the game, I thought to match my
general feel of the game being speed based, I’d add enemies which would
compromise this, coming in intensely fast and upon collision would
instantly destroy the player, making it more sense to avoid them.
After the general basics and such of the game, I started to make tweeks to
my game, which include revamping the room design, keeping a similar type
of design, but more detailed and far more eye catching.

11. To make my game seem more user friendly and game-like by implementing
a start menu and death screen within the game. Keeping a similar design to
the main room with the dark, spikey and contrasting red colours
I made a start and death screen which would use the contrast of red with a
dynamic background which would be eye catching and intriguing

12. To further ramp up the difficulty and duration of my game, I decided to add
in a boss battle in the end which would last a short while and potentially
take a couple of tries before accomplishing a win.
Programming a shield and different damage areas from the players bullets,
hitting the ship increases the damage.