It cracks me up! I like the idea, generally (realizing that this is presently just in rough-draft form, and the implementation will be smoothed out for the final version). I'd like to suggest:
1. the red indicator needs to be doing a more fluid gesture, rather than just the sudden jump from top to bottom. It's too difficult to follow if it gets to where you're supposed to be before you know where it's going. Kind of like trying to stop for a red light without having the yellow light appear to give you a warning, the driver isn't able to anticipate a required action, since there's nothing indicating it until after it's already been required.
2. there can be various other motion changes, across varying ranges and speeds and locations -- full shaft, partial shaft, top only, bottom only, rapid at top but slow at bottom, etc. However, the more complicated you make it, the less likely the vid in its entirety is a work of exciting porn and the more likely it becomes instead a guitar-hero type game in which the complex hand movement requirements are heavily distracting from the previously enjoyable sexy ladies scenes.
3. I'd suggest COMBINING this meter with the "traditional" pulse-meter. Just run the new one on the right of the screen as you have done; and the old one across the bottom of the screen as many previous vids have done. This will help with concern number 1., above, by giving a bit of an advance view of what's coming up, and will also help with the concerns that many others seem to have, of preferring less obtrusive text and less invasive presence of "instructions." By making it all symbolic rather than verbal, you get it to be more of tacit game rather than an overt one.
4. In that vein, it's possible that the stroke-meter that pulses across the bottom of the screen could BE the dick-meter that you have on the side of the screen. In other words, scrolling right-to-left, across only the bottom of the screen, in proper rhythm, would be sinusoidal curves, or similar, indicating many aspects of the required stroke: height of stroke (by height of wave crest); speed of stroke (by rate of pulse as it travels from right to left); intensity of stroke (by color, or by variation of a "hand" indicator); etc.. Others have suggested similarly.
I know I'm being persnickety. It's all just suggestions. Have fun with it! Take or leave ...
