Cash extractor
The game itself is good enough. But it's clearly designed to make you pay money. You'll do well matched against players that are pushovers. Then once you have some coins, you'll be playing terminators that will take all your coins just to the point of being broke. Magically, now you'll be matched against pushovers. The algorithm is wildly obvious. Most of the players are likely AI. Good game, but give players who don't want to pay a chance to hang in.