If you're looking for a game that doesn't need much thinking and action, here's for you. It's a 2D shooting game that shoots monsters and coins can be obtained from it.
Coins are obtained from killed monsters and each stage has a corresponding boss at the end of it. The higher the round you're in, the harder the monsters can be killed. Buy guns and merge to create an upgraded weapon. It's better to upgrade your weapon continuously to catch up with the levels of monsters as well.
There are hints at the start of the game. Just press the center button to shoot and the player will instantly aim at the monster closer to you. Each stage cleared has 3 sets of cards and you'll choose one to have your reward.
The game is a little slow and came to a point wherein I let the monsters come closer before I shoot them. The music somehow does not match with the game and I'd rather play it without music.