In the past few years there have been released a handful of indie games which share a kind of common form and aesthetic, one that strikes a chord with me. This design space is represented in my mind by Kairo, and the upcoming Fract and NaissanceE, though it contains many more.
The quality these games have in common is use a first-person perspective and an experience based around architecture and soundscapes, working in concert to elicit some aesthetic or emotional response.
Unlike Myst and some more recent games it inspired, these games have little or no explicit story; not necessarily even "environmental storytelling", which games are so good at. Rather, they chose to let the player's movements, decisions and interactions build their own ambiguous narrative.
Also unlike Myst et al., the spaces presented in these games are not an attempt to render a lifelike world, but are more abstract expressions of architectural form. Frequently, even colour and texture are eschewed to let the geometry of the spaces speak for itself. (Those colours or textures which do exist are sufficiently abstracted that they may carry their own, novel semantics.)
Though photorealism is not a goal for these games, the spaces they allow the player to inhabit possess no less character or sense of place. Instead, this can come from several alternative sources. Primarily from the players perspective, sound can be the most evocative signifier of place. Music was used in Riven, but the real atmosphere came from the singing of birds, from the echoing movement of machines, from the insects in the trees.
In this space, too, sound provides a vivid ambience. The formulation of environments in terms of primitive geometry is harmonious with sound of a similarly minimalistic construction. The soundtracks to these games is often abstract and perhaps best described as sound sculpture rather than music. Sound can be systemically tied to location, so that it is impossible to think of one without the other. In some sense it can take the place of scent.
When spaces are this abstract, the line between diegetic and non-diegetic sound begins to blur. The fluttering and splashing of movement in Antichamber fit perfectly with its richly stark shapes and playfully consistent illogic.
Taking this notion to extreme, every space in Activate The Three Artefacts And Then Leave is the same combination of vast, ill-defined cavern and tight, crystalline corridor, with the regions individuated only by the presence of characteristic drones. Only by listening to the precise mix of ambient noise does the player have any hope of navigating the space; like following a trail of scent.
This seemingly restrictive design space is actually expressive enough to communicate a multitude of ideas to the player. Whereas Kairo, Antichamber and (by the looks of things) Fract evoke a lonely, contemplative curiosity, Increpare's The Clotted Island and Three Artefacts are claustrophobic and panic-inducing, and play like a cross between a migraine and straitjacket.
At an opposite extreme, Zineth is, in its creators' words, a celebration of "speed, movement and twitter".
Fract is not yet released, but on the horizon lies another design space which I believe is an further evolution of these ideas. The upcoming Memory of a Broken Dimension shows a world with a striking presence, but so abstracted from realism that even the geometry of the world is only implied. Forms coalesce and sublimate as the player looks at them, but always inviting exploration.
The in-development Dirac may possibly share some of these ideas of abstracted representations of space, though it's maybe too early to say.
To my knowledge, this kind of aesthetic space is not found anywhere outside of games (and perhaps some animated cinema). I think it represents an important strength of the medium. There is a lot of room for future exploration.