One art style I find particularly appealing is any style that uses hand drawn, frame by frame animations. These are often used in 2D games such as those in the fighting and platforming genres although they have also found use in some 3D games (Isometric games in particular). One game in particular that captures this perfectly in my mind is “Skullgirls”.
Skullgirls uses a hand drawn art style that focus on extremely expressive animations and unique character and environment design. Every character and area had an interesting twist and was animated with a high level of detail despite the small 0.1 – 0.75 second windows the majority of the animations take place in due to the way fighting games have to operate. Taking a look at the sprite sheets or running the game in slow motion lets you truly appreciate the minutia that has gone into the Art direction of the game and whilst these animations are exceptionally fast, it is usually possible to see them for what they are and the extra detail that went into their creation is justified. Skullgirls was trying to create a world with a good sense of levity and a small amount of seriousness mixed in and its hand drawn, cartoon inspired art style fit this perfectly.
Another good example of this style is “Dont starve”, which is a survival game with a heavily “Tim burton” style of grim cartoon-like visuals. Despite its overly expressive and cartoon like art style (Two elements that usually distance the viewer from immersion and therefore any real sense of danger that horror rely on), the game manages to create real moments of tension and borderline fear thanks to a strong use of lighting, sound design and small but effective animations (Shadows of hands grabbing at the edge of the darkness and small glowing eyes occasionally appearing for a few moments). Its expressive visual style helps offset the otherwise oppressive nature of the world, giving the player a break in-between tense and horror rich moments.
The two examples I have given are both trying to achieve something quite different and through the use of hand drawn styles have both managed them very effectively. The benefits to the style (Expressive animations, Unique character and world design if done correctly) can work well for many games and if created with expertise can adapt to any tone or theme required.
Analysing tone and theme in relation to art styles might be a good idea