This will be about which games take a short amount of time to complete with a great prize!

1. Crossout
With the quest to get 10 battle wins, which took me around 30 minutes you get 700+ gems. Amazing right? This game is all about building up your car, making it look cool, and stronger to send it on battles and destroy other cars. Become the best, and even earn missile launchers to be put on your car. The more parts for the car you get, the harder you are to kill, and you can smash the other players into oblivion. You will level up, which will earn you even better parts, and the graphics on this game is AMAZING! It doesn't take much to get it going, an old PC could probably run it. Overall, this is an enjoyable game, for a wonderful amount of gems.

2. Divine Storm
For an hour or so of work, you get 200+ gems, and that in my opinion is definitally worth it. You start out as a class of your choice, and you have to do tasks in order to recieve XP to level up. You get better items, and gear whenever you kill enemies, and defeat quests. Become the one, and only god of the world, and try to conquer the game. This will take a lot of leveling up, and skill to do, but it can be accomplished. Try to become the best at the game, and overall just have fun. This game isn't as bad as I thought it would be, and is quite fun at moments. So fun + reward, worth it. May not be as much as you want, but it's still easy to earn, so go ahead... Try it out!

3. Star Stable
This game is incredibally easy, and all you need to do is advance to level 5. Within an hour, your task is complete, and you will earn 180 gems. Sadly, this seems like a girl-only game, without a male role in it. You can still try it out, it's about a girl enjoying her time on an island called, "Jorvik Island." This island is full of people passionate about horse riding. Jorvik island is known a lot about horses, including horse breeding, and more. An evil corporation comes to take over the land, and you must save the people, and horses on the island. Become the best horseback rider, and save the island!