Greedy Guns is damn fun as it is difficult. It's not quite Metal Slug difficult where you die in one hit. However, given the low damage of the guns and the amount of enemies and projectiles that can take up the screen, Greedy Guns is one hell of a challenge for even veteran gamers.
It's a graphically good game. The colors and effects are bright and vibrant, although it can be hard to focus when several enemies and projectiles are on the screen. Music and sound effects are great, as they should be in games such at these.
Greedy Guns offers full controller support, and is the preferred way of playing this game. The dual-stick shooting aspect is kind of awkward. Aiming with the mouse is always easier than with a controller. However, as far as the rest of the game's execution and playability, the controller is optimal to survive.
I don't know what else to say, VERY good work on this! Hope the Kickstarter's a success!