Release candidate for 0.5.7 has been released. 0.5.7 will be released in one week so we are releasing a test build now. You can play the test build by selecting the beta version of the game on Steam.
We are releasing this test build to catch the most glaring errors before 0.5.7 is released. If you find any new bugs or new features that aren't working please let us know, either in the comments or on our forums in this thread. If you experience any crashes the launcher should give you the option to report them to us, if it does please send us your reports.
If there aren't showstopper bugs that we can't fix in time, 0.5.7 will release in one week. The major new features are the new crash reporting system, timeline tab and other editor GUI improvements, as well as some adjustments to address low performance.