This terrain idea is too difficult

My idea for making terrain is turning out to be too difficult to implement.

You can see the moving terrain test here. It lets you fly and die when you hit the ground or a cloud. 

I thought that by making the terrain out of single pixel wide pieces, I'd be able to make lots of interesting terrain and do it all custom - but within the time constraints of getting this done, I can't come up with good math for making interesting terrain that works for the gameplay.

For the gameplay to work, there need to be valleys that Cupid can dive into (and be able to fly up out) so that he's low enough to shoot the bunnies on the hills. The difficulty of the game all depends on how this fluctuation works. There's probably a way to do this with combining sine and cosine waves or with some of Godot's advanced random noise functions, but these solutions would require me to learn and implement math stuff.

What I tried was having some states of going up-edness and down-edness and gradually increasing or decreasing the up or down velocity - but I couldn't get it working. This too might require more time/math than I can devote right now.

Especially since I want to have a parallax scrolling background (which I believe displaying is easy) and I need to draw something that matches with the terrain in the foreground. 

Gotta get stuff done, so it's time to simplify!

This is a video of me showing how the 1 pixel wide terrain works