Here is the full list of all 25 Luckslinger achievements.
Beat the game
Collect all the vinyl's
Kill an enemy with an explosive barrel
Chug 60 beers in 5 seconds
Look what the cat dragged in
Beat the B side
Get a lucky ending
Kill a boss with a knife
Kill a boss with a dynamite
Kill a boss with a boomerang
Kill a boss with a shotgun
Kill Sean before he destroys the earth
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Beat all the duelists
Get 650 points with 1 skateboard combo
Get 840 points with 1 skateboard combo
Kill a boss with a minigun
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Kill a boss with the golden knife
Get the best possible ending