Hikou no mizu wasn't packaged for any GNU/Linux or *BSD distribution yet, you may want to download precompiled binaries or the development version for the most courageous ones ;).
Dynamically-linked binaries were built for some architectures and OSes. Currently, the repository contains packages for GNU/Linux i386, amd64 and FreeBSD amd64, you'll find tars for every stable release. You can freely browse the repository or use the dedicated download webpage.
The game may not start the first time you launch it because of a lack of installed dependencies, these are quite common however and you should easily find them in the repositories of your distribution. (see compiling for the list).
Hikou no mizu runs from where it's built. The latest stable release is 0.2dev.