Blunder Dog

You play as Knackle the pirate dog, who was once part of the jolly crew known to the world as The Scurvy Dogs. However, now Knackle finds himself  being forced to walk the plank by the crew he's spent his whole life, all because you accidentally put 4 ice cubes in the captain's drink instead of 3. As he is drowning, he hears a faint voice and prays for his life before everything fades to black. Waking up washed up on shore, he finds a talking gun and a demand to obtain 50 tons of blood to give to the god Sanguikan, who saved his life. As he wanted nothing more than to get revenge on those who betrayed him, he saw no reason to argue and set out into the world to get blood from those who wronged him.

IMPORTANT

There's no built in tutorial for button presses so I'm putting it here:

LMB: Fire Gun
RMB: Dash
Q: Vacuum