Space Evader 2000
Space Evader 2000 is an avoid-em-up where the player must navigate their spaceship through space debris and survive as long as possible.
This game was made during the QUT Game Development Club's mid-year game jam. It was a casual jam that lasted 5 days, Monday to Friday.
I designed and developed the entire game within this time. Except for the font and sound effects.
The game can be played here.
Design Notes
Initial Concept
The initial concept for Space Evader was to make a simple avoid-em-up.
A variety of objects would fly towards the player, they would aim for the area around the player and continue in a straight line until disappearing off-screen.
Initially, the objects would be small objects that were slow. They'd gradually increase in speed and new objects which were larger would appear. Larger objects would almost always move slower than smaller objects.
The game's difficulty would increase as time went one. In the upper diagram, USM is used, and increases as time goes one. This would control which objects could spawn, and the overall speed of the game. So as the game went on, new objects and larger objects would begin spawning.
Implementation
The first thing to do was setup the core gameplay.
A player which followed the mouse and moved
towards in when clicked and large boxes that
moved towards the player were simple enough.
Creating the USM to control object speed as well as
spawning rules was also simple enough. Each time
an object would be spawned, the USM would be
divided by the size, if it was above a set minimum
speed, the object would spawn.
This initial implementation made objects spawn slowly, as if there were 7 objects, there was only a 1/7 chance of an object spawning when one could. So very few objects spawned and were slow when they did. To increase difficulty, the spawn rate was increased, however this made difficulty vary wildly. Sometime no objects would spawn, and sometime the screen would be flooded with objects. Instead, a new system was implemented, this system controlled which objects could spawn. So, instead of choosing any object and checking if it could spawn, only objects that would move fast enough would spawn.
This provided a steady flow of obstacles that increased in speed as time went on, and introduced new obstacles at slower speeds. At this point, the rate of obstacles spawning, their speed and the size of objects that could spawn at any given time just needed to be adjusted to balance the game, and the player and obstacles needed to be drawn.
The images on the left are the final sprites drawn for the obstacles.
Other than these, I starry sky background was used, and an explosion sprite-sheet. In addition, sound effects were retrieved from zapsplat.com.
Reflection and Further Changes
This was the second game jam I participated in, the first that was conducted remotely and the first that everyone in the jam was working on a single game. The idea of the jam was to create an arcade of several small games. So everyone would work on smaller individual projects and combine them together.
This proved to be an interesting hurdle itself. Since each project would be combined later, every change to the unity project settings needed to be tracked, especially Tags and Layers. In the end, I decided to only use Unity's default tags to avoid conflicts later on. This lead to it's own problems with me not realising 'EditorOnly' actually changed the properties of gameobjects.
The casual nature of the jam made it easy to work in and easy to motivate myself. I don't have great programming skills or artistic ability, but being able to work at my own pace made it easy know where the project was and where it was heading. Overall, I'm happy with the result of Space Evader 2000, but realise there is more that I could do with it.
If there was anything I wanted to change with the game, it would be to add music, create more obstacles, with more variety for each sized obstacle. And, lastly, fine tune the difficulty more. With a more dedicated system to determine object speed, object spawn size and object spawn rate, the game's difficulty curve could be altered and result in major flow improvements.