I'm not sure what is up with those checkpoints. I already know what checkpoints to die on and why, but there have been times when I died but somehow didn't grab the checkpoint even though I was touching about 80% of it, and other times when it works fine even though I was touching only about 45% of it. What's up with the weird collision on these checkpoints? Is there a consistent setup that I am missing? Help would be very much appreciated.
Yes there is a consistent setup for almost all checkpoint based on background, just watch closely any of the tower run:
https://www.speedrun.com/VVVVVV/The_Tower#Any
I personally never use them and just play safe, and only loose 1.5sec max so i doesnt matter much.
The problem is that the game is not continuous, but divided into 1/30 second increments (or frames). That means sometimes you'll be 1 pixel away from the checkpoint on one frame, on the next frame you'll overlap with it by 9 pixels; other times you'll first be 9 pixels away, then overlap with it by 1 pixel. To activate the checkpoint, you have to have touched in on the previous frame. If you die on the same frame you touch it, it won't activate. So for some checkpoints you can go earlier, because the frames line up neatly, but for some checkpoints you'll have to go a bit later.
What decides whether or not it lines up well is which platform you fall / flip off of, so you should try to replicate exactly what the top runs do, because they (for the most part) line up the checkpoint deaths well. Also remember that the checkpoint deaths don't have to be frame perfect, even ones that don't die on the ceiling spikes still save time.
My best advice is to find visual cues (e.g. the moment a platform goes off screen) to time the input to drop onto the checkpoint. You'll have to experiment a bit, but it's not too hard to find relatively consistent visual cues.
PS: @Mindwaves each checkpoint death saves 0.7 seconds optimally, so the 6 checkpoint skips will usually save around 4 seconds in total.
