Recs.
Updated
Cuphead is a run and gun action game, consisting mainly of boss fights. It's inspired by cartoons from the 1930's, and the visuals and music are created using the same methods as cartoons from that era. The gameplay is very active and fast-paced, so expect to die a lot.
SpecsUpdate
Pros
Pro Creative and challenging
The gameplay is centered around defeating bosses, each boss has unique abilities and varying difficulty. Often there is a lot happening on the screen at once, which can be disorienting- this is part of the charm and challenge. You really need to be quick and pay attention to your surroundings at all times, otherwise you will die a lot more (though you'll probably die plenty of times anyway). The sequence of attacks from the bosses changes around at random, so there's no way you can be 100% sure of what will happen next even after you've played against a boss a few times.
Pro Excellent co-op
While it can be overly frustrating when you're playing alone, Cuphead also has local co-op for two players, making your adventure easier but a lot more enjoyable. The boss fights become shorter because together you deal more damage, you don't take needless hits because you can cover more blind spots, and you can even resurrect the other player by touching their ghost if you die. This way you still get the satisfaction of a challenging fight, but it won't be as disappointing if you fail. Even if you're not into challenging games, co-op can be a way to enjoy Cuphead.
Pro Really beautiful old-school art style
The backgrounds were done in watercolor (real life watercolor, not digital painting), all animations are hand-drawn, and the music has been recorded live. Cuphead is a work of art as much as it is an exciting game.