Human Crasher finally lets you abduct humans and turn them into an energy source. It's a game that says "Serve your motherland, alien pilot."
It combines two things: on one hand it's a UFO dodge 'em up, on the other it's Flappy Bird with a tractor beam.
I'll explain. Your flying saucer travels across the screen on its own accord. Below you are the unseeing humans walking along city streets, or enjoying the summer sun while floating in the sea - depending what level you're on.
When you hold your finger on the screen, your tractor beam sucks up everything underneath it.
You only want the humans, but speedboats, rubber duck rings, tanks, and cars will be brought up as well. If any of this debris - everything that's not a human - hits your ship you'll take damage.
While doing this, you'll need to dodge the planes that will fly into you, bringing you more damage. Sometimes, tanks will also fire shells at you from the ground. You need to swipe down on the screen to avoid these direct attacks.
Once you eventually take too much damage, or run out of power for your tractor beam, you return to your docking station.
Here, an alien with an upside-down face will offer you repairs and upgrades. You can get more power, better protection, add spray paint "tattoos" to your ship, and even buy better flying craft.
Human Crasher has a standard gameplay loop, then - dodge and collect, then spend to upgrade, and repeat.
But, unless I'm catastrophically bad, I found that it was a little too hard make any progress. The currency I collected during each mass abduction attempt went towards repairing my ship, and so I was getting nowhere.
It felt, to me, that it was designed to be this way to encourage you to spend out on the IAPs. Doing so gets you the money needed to upgrade your ship without any of the effort.
It might be worth a go at Human Crasher to see if you fare any better than me. Plus, the music is great, and it does have a similarly high-skill ceiling as Flappy Bird, if that's your kinda thing.
You can purchase Human Crasher for 69p / 99c on the App Store.