How much time was saved by using a no-death mode, by your estimation?
A simple estimate would be to add up all of the time spent in cutscenes, as that is the primary time saving feature of NDM. Cutscenes alone take at least a minute.
If you wanted to get a little bit more in detail, you would need to factor in time that can be saved from dieing (a good example is death abuse in the tower to make the camera scroll faster), along with time that can be saved using save abuse (one example is that the cutscene in the communications room with Violet can be skipped by going one pixel past the cutscene trigger, saving the game, and then resetting).
So a rough estimate would be ~1minute I would say, which is quite significant considering the total length of a speedrun.
Another thing that might eventually come into consideration for a TAS is the differences between the 1.x and 2.0 versions, primarily concerning the collision detection of enemy sprites. Let's take the room Security Sweep in Space Station 1 for example. It was pointed out that in order to get make the first cycle of the bouncing ball, you would need to pause a short amount on the previous screen in order to be in the right position entering the room. In 1.2, this is not the case, because in my realtime speedruns of this game I was able pass the sweep with zero hesitation on the previous screen using the same room strats.
Probably the most glaring example, however, is in Space Station 2, on the screen "Lighter Than Air". In 1.2, if you hugged the wall going from that screen to the next (Level Complete), you would just barely miss hitting the cloud on the next screen, while on 2.0 you will hit the cloud every time without fail.
Granted, these differences are very small, especially considering that 2.0 has a new time-saving glitch that allows you pass through the inversion planes on "Three's Company", and "Three's a Crowd" by merely spamming flip (seems to only work on inversion planes that are close to a flippable surface), which, I am fairly certain saves more time than having to merely hesitate a bit every now and then.
While chances are that these version differences will not be explored in depth until hourglass is capable of running flash games, it is something worth keeping in mind at least.
I decided to test out TASing VVVVVV 2.0 (1.2 wont work yet because it is made with flash), and managed to beat no death mode in 13:57. I made plenty of small mistakes though, and Hourglass's savestates crash the program far too often, so I wont be putting the effort into a well optimized TAS anytime soon.
Some small notes:
-I used hourglass r71
-Even though the the game video runs at 30fps, the music will clip horribly unless you run it at 60fps, so I recorded the TAS at 120fps because it seemed to make my savestates crash the program less often (might be placebo though).
-You need to have a quick save, and no death mode unlocked for this movie to sync properly.
-Disabling Multithreading causes VVVVVV to not load, same with disabling direct sound creation
-I didn't notice any difference between using "Allow" and "Wrap" on multithreading.
-I think all the other options are default.
Well anyway, you can download the wtf file here. Have fun and what-not.