Portal 2 SP Challenges [Column Blocker - 4 portals] 256 colors

Portal 2 challenge mode map "column blocker" solved with 4 portals and 256 colors in 424x240 resolution. My computer is slow, and the challenge mode does not allow recording with host_timescale, so the scripted elements (including the movement of the cube when moved around) are jerky. It is a glitch in the demo player of the Source engine. It occurs when a demo is replayed at a higher framerate than it was recorded on. What? I create videos like this. If you did not like it, please unsee it and watch something else instead. Though in all seriousness, this is not really what I planned on publishing next. I just did it for fun. I'm working on something that takes a bit of time. Gameplaywise, it is not a particularly special video either. In fact, many have solved this room in 2 portals. However, I have never mastered the "bunny hop" technique required for jumping over large gaps, so I only did the "clever" part of optimizing the portal count and forfeited the "nimble" part that is not my specialty. The demo was recorded at 640x480 resolution with lowest possible settings so that it could be recorded with maximal rate (given the lack of host_timescale). Then I replayed it in 848x480 using highest possible settings, at a constant 30 fps rate (host_framerate and startmovie). I did not use a higher resolution, because I was going to downscale it to 424x240 anyway. I did not use a higher frame rate, because it would have aggravated further the demo replaying bugs of the Source engine. Then I downsampled it into 424x240 using lanczos filter for spatial scaling implemented in MEncoder; and dithered it using Yliluoma-2 positional dithering algorithm implemented in Animmerger, with a dynamic 256-color palette chosen with Neuquant neural network quantization algorithm implemented in Animmerger. The palette is constant for every 500 frames. (So it changes a total of 10 times during the video.)