I love the game "Plague, Inc" by Ndemic. Supposedly there's an update coming that will introduce a Zombie virus.
Such a fun and challenging game.
Some of the achievements, by a look online, NOBODY knows how to achieve them.
There are achievements like "infect the astronauts before they launch into space" and Get the US to nuke China & Russia.
Someone online said that nobody outside the Devs seems to know how the hell you do that.
I've never seen a game before that had achievements that was that guarded of a secret. lol
I recommend Pik Pok's games "Flick Kick" (which is flicking a football through the goalposts, often factoring in wind conditions) and "Flick Kick Football" which is a soccer one where you have to flick it into the net, often curving around defenders.
Both are extremely addicting and I've spent a lot of time on them. lol.
Oh my God, I love that game! Out of curiosity, what's your highest score?
What is your Game Center ID? I'll add it to the community list in the OP.
Here are my scores on Arcade:
Flick Kick Field Goal: 165
Flick Kick Football: 66