This is the version of The Last Tango as it stood at the end of the 48-hour compo. Unless you are judging the compo, you'd probably rather play the current version, which has improved controls and some minor bug fixes.
If you get a "Bad file length" error, it means the connection is dropping packets between you and the host. The Unity WebPlayer has this as a known issue. Disabling your Unity caching usually fixes it, but if not, download the desktop version.