Link to .capx file (required!):
CAPX by email.
goo.gl/oT46J
Steps to reproduce:
Hello Mr. Ashley,
I'm having trouble with this game, because I don't have idea of why the hell the enemy sprite is increasing his size on the temporary canvas.
I did a test on a specific step of the project, making on the start of the screen to the layer scale to 200%, was not what I was looking for, so, I decided to undo all the job, and after it, the enemy still scaling but now, over the time, and I watched all the code, including the XML to find any mistake or residual code, and found nothing.
Edited: 
Ashley , I found the cause, but it's more weird than before... I set the enemy to play an animation without loop, and everytime he finish the animation, shot, and restart. After trying to isolate the problem, I disabled the restart animation action and it stoped to resize, but stoped to loop the animation too...
Also, because of that other problem I had, while editing the sprites outside the Construct 2 and reloading them, the first sprite was not updated, and after reloading this specific sprite, it update his size to be a little bit bigger than the others, but on the original image, it's not. So, all these steps whould contribute for this problem.
If you have the first frame bigger than the others, and restart an animation manually, the sprite will increase or decrease his size.
Observed result:
The enemy ships are scaling when it's not supposed to happen.
Expected result:
Still the same size.
Browsers affected:
Chrome: yes
Firefox: yes
Internet Explorer: yes
Operating system & service pack:
Windows 8
Construct 2 version:
R124