Aquatic webgame Subbania is Das Boot reimagined as a Metroidvania
We're constantly being told that HTML5 is the future of webgames, but until now actual fully-fledged games developed using the language have been thin on the ground. Enter Subbania, a game two years in the making that plays like a mixture of Metroid, Aquaria, and Das Boot. You can buy it for $2.99, or download a demo here, but you'll need the Chrome browser (for the demo at least), as it runs like a schweinhund in Firefox.
Developer Ektomarch outlines the frustration of working with HTML5 and Chrome on the frank blog post that accompanies the game launch, but the result is an atmospheric underwater shooter/exploration game with "118 levels, 25 songs, around 20000 lines of code, so many enemies and entities that I'm not even going to bother counting them, and a few solid hours of content." Also: demons. Have a look at them in action in the soggy trailer.