While only released in the US and Canada, it's 1,000G can all be earned in around 15 minutes with a guide. And it's a puzzle game for $2.99. What a bargain!
Another puzzle game, this time it's a worldwide release, it's $1.99, and it takes around 45 minutes with a guide for all the 1,000G. And only has 10 Achievements, 100G each.