Playtesting and bug squishing…

With quite a significant amount of Space Invaders working, I thought I would take the opportunity to have a sprint for playtesting and resolving the bugs this process identified, along with a few issues I had already spotted but only logged to date.

Whilst the following issues were not huge, they did have an overall negative impact on the game and it felt good to get these resolved.

BUG #26: Game Over – When the player loses all of their lives the menu doesn’t appear until the remaining invaders have landed on the planet.

Space Invaders’ end condition is met when the invaders reach the lunar surface, one could argue that the player losing all of their lives is also an end condition, this is true, but primarily because the player then loses their ability to stop the invaders from reaching the lunar surface.

My initial efforts had focused on the lunar surface end condition, if a player lost all of their lives, they had to sit there and wait until the invaders finally arrived on the lunar surface, an unlucky (noob) player could have quit a wait before being able to play again!

The issue was resolved by having the UIController listen for an additional event which would be triggered when the player lost their last life. Whilst the menu now appears immediately, the invaders continue to march back and forth in the background until they land on the lunar surface, this is in keeping with the original game and makes the end condition experience slightly more enjoyable, or at least, more interactive.

BUG #24: When the player loses their last life, the Command Ship, if present, continues to fly off the screen but has no audio.

As it happens, this was not a bug but intended behaviour. In the original game, when the player loses their last life, all of the sound effects in the game stop playing, the command ship continues to move off the screen and the invaders continue to march until they reach the lunar surface.

BUG #22: CommandShip stops moving when the InvaderFormation lands, but the CommandShip audio continues to play.

This was quite possibly one of the most irritating bugs found to date. When the invaders arrived at the lunar surface, the end condition was met, the command ship movement was being stopped but its flying sound effect was not, this would continue until a new game was started.

The issue was resolved by not stopping the command ship’s movement when the end condition was met, this allowed the command ship to move out of the visible playspace and then be reset which, thankfully, stopped the flying sound effect. This behaviour is now in line with the original game.

BUG #20: InvaderFormation continues to play marching sound effect even when the player has been hit/destroyed.

Whilst the invaders stopped moving whilst the player’s death sequence played, the marching sound effect continued to play, this provided quite an odd experience as the player’s eyes and ears were telling two different stories.

The resolution to this issue was to stop the sound effect being played once the player was hit and was handled by triggering an event and having the invaders’ InvaderFormationAudioController listening for it.

BUG #21: InvaderFormation continues to animate when the player has been hit/destroyed.

On a personal level this issue didn’t bother me too much, I thought the invaders actually looked quite cool poised ready for action whilst the player’s death sequence played and continued animating themselves, but having checked the original, this wasn’t how it was done. When the player is hit, the invader’s animations should also stop, just like the sound effect issue above, the same approach was taken.

BUG #23: Stutter sound effect is too quite.

I have yet to find a better way of describing this sound effect. When the last invader is destroyed in a wave there is a little stutter sound effect that plays. Initially I thought this was supposed to represent the engines on the rocket ship as it descended on the left hand side of the screen at its timing seemed to fit perfectly (41-43 seconds in the clip below);

However, through playing the original game I discovered that this sound effect plays even when the rocket ship has landed on the lunar surface. With this in mind I came to the conclusion that the sound effect was supposed to represent something else, although, to date, I’m not sure what.

Having introduced this sound effect at the correct moment during the game play I noticed that it was far too quiet compared to the other sound effects in the game.

The issue was resolved by normalising the audio clip using Audacity, which I had done with the other sound effects but must have missed this one.

On a related note, if anyone has any thought as to what this sound effect is supposed to represent I’d be glad to hear from you. I still wonder if it is the engines on the rocket ship after all and perhaps the fact that it still played after the rocket ship lands was just a bug in the original game but I’m not 100% convinced on my theory.

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