Alien Theory was a small prototype I made in Construct 2. At the time I had been playing a lot of Super Meat Boy, which combined with playing a lot of Frozen Synapse resulted in me trying to combine the two. I spent a few months working on the core mechanics but soon realized that the pixel based movement used in Construct 2 meant it’s collision detection fluctuated wildly when the frame rate dipped. Playing scenes on repeat where the actions had to be exactly the same (sometimes missing bullets by only a few pixels), the player would sometimes hit the bullet at 60FPS but miss it at 50FPS.
I eventually ported the thing over to use box2d so I could use their more accurate collision detection, which also meant ripping apart 90% of the code I had. Another 2 months or so later I ended up with a prototype that somehow holds together without exploding at the seams.