PuzzleScript is a recent project by indie game developer Stephen “increpare” Lavelle. It's a flexible yet minimalistic, open-source, HTML5-based game engine which is most suited for designing puzzle games. An online editor is available at the project's homepage.
Why am I posting this here on Ancient Wonderworld? Well, because that's what the games will look like, for example:
Collapse by Terry Cavanagh
Heroes of Sokoban by by Jonah Ostroff
In fact, all game graphics have to fit into a 5x5 pixel tile grid. Neat, huh? If you're still not convinced, then check out the latest PuzzleScript titles here, btw.