Edit 6/18/2014: I'm so glad everyone liked the review! I hope I got the devs some extra money...they deserve it!
I definitely milked every ounce of entertainment and replay value out of this game after I bought it by going for A+ grades on all of the levels and 100% achievement completion, but despite the tedium that I thought that that would entail, I enjoyed every second I spent playing this little indie gem. It has a convoluted sense of humor akin to a Yotam Perel or Edd Gould cartoon, but with more f-words. The gameplay involves 2D stealth platforming similar to Mark of the Ninja, but with a pixel-art style and a noir theme. The music is great, and makes you feel like a modernized incarnation of a gumshoe detective as you punch out guards and rewire electronics while trying to solve a twisted, oppurtunistic murder.
My personal score for Gunpoint is a 9/10. There isn't much true replay value to speak of, which takes away from a perfect score from me, but like I said I had a lot of fun replaying levels and achievement hunting for over 15 hours after I had beaten the game.