Thanks for checking it out, I'm glad you enjoyed it! Yes I believe the original had the flapping mechanics you described where upward velocity was just set instead of incremented, but I suppose I went the other way because I found it a bit more interesting. Rather than being only about timing, you had a bit more control over how high your flap would launch you.
Anyway what about rendering the pipes is getting you stuck? From what I can remember, spr() or sspr() is used to draw sprites to the screen. Are you referring to something else such as pipes spawning perhaps?