It's what I consider a rogue-like-lite-Quake-like. Need I say more? Well I shouldn't, but if you insist... Actually, I'll just let the Dev do it in the next paragraph. All you need to know from me is that I have been playing this game since alpha and I absolutely love it!
From the Dev's website:
"Tower of Guns is a fast paced randomized FPS for the twitch gamer, a short burst "Lunch Break FPS" not unlike Binding of Isaac mixed with Doom 2. If you're gonna win, you're gonna do it within an hour. That's a big if though... it won't be easy. With random enemies, random power ups, random bosses, tons of unlockable items and weapons...and even random-level compositing--You never know what to expect! So grab a rocket-launcher, slap a shotgun-modifier on it, pick up a hundred stackable 'double jumps' (or centuple jumps at that point, I suppose) and get to conquering the Tower of guns!"
So, if you watch this video and think to yourself, "that looks like fun...", just go buy it. Don't wait for a sale, don't go to the bathroom, just get the game and start playing it immediately. You can thank me later.
There are at least 7 ways to buy the game, so if you have digital distribution preferences you're probably covered. Go to the dev's site at http://www.towerofguns.com/ to see your options. Personally, I love Humble so I get a DRM-free + Steam version of the game and the dev gets a bigger cut, but buying directly from Steam often does more to get the game exposure on Steam.
Like the music? Check out the album at http://mikemirabello.bandcamp.com/