Katawa Shoujo is a bishoujo-style visual novel set in the fictional Yamaku High School for disabled children, located somewhere in modern Japan. Hisao Nakai, a normal boy living a normal life, has his life turned upside down when a congenital heart defect forces him to move to a new school after a long hospitalization. Despite his difficulties, Hisao is able to find friends—and perhaps love, if he plays his cards right. There are five main paths corresponding to the 5 main female characters, each path following the storyline pertaining to that character. The story is told through the perspective of the main character, using a first person narrative. This game uses a traditional text and sprite-based visual novel model with an ADV text box. Katawa Shoujo is under development by an international team of amateur developers, and will be released free of charge under the Creative Commons BY-NC-ND License.
Gameplay-wise, this is a pretty traditional Visual Novel (VN). While it has five main heroine routes, the history doesn't repeat too much, as the first act of the game conveniently changes with the choices you pick, and once you end on a girl's path, the game locks you on that path with a storyline set apart of the rest of the girls, except for a few shared events that are pretty welcome.
The writing, the music, and the artwork of this game is exceptional for a free game, the only shortcut they took was the use of photographs for some of the backgrounds (the ones in the CGs were all hand-painted, though), something that several other VNs have also done (even commercial ones, such as the well-acclaimed Tsukihime).
Overall, you get good feelings while playing this game, and it tells you a pretty touching story of superation and regaining self-esteem, entwined with a few erotic scenes that can be partially toggled off in the options menu, and while that's the selling point of these kind of products, their inclusion doesn't make the game feel cheap. It's also pretty long, each path took me about 6 hours of gameplay from beginning to end. The girl's personalities are complex and don't fall into easy japanese stereotypes as happens with many other games in the genre. The men in this game, however, tend to fall on the silly/cartoon side of the spectrum, but they all have original and different personalities.
Many of the concerns people have expressed with this game are shared with other Visual Novels: it could have more choices that affect the story in decisive ways, it could have more endings/girls, it feels more like reading a book than playing an actual game, and it seems all the interaction you do is pressing the space key for hours. Some other people would also prefer if the game had even more/less spicy content.
In sum, if you enjoy VNs with good writing, you'll probably love this one.