Testers are appreciated, as ever.
There are already quite a few of you who I've been playing with in the evenings, and we've found a lot of minor issues while doing that.

Copy and paste build instructions for ubuntu/debian.
http://www.hedgewars.org/node/2215#comment-15049

approximate feature list
http://hedgewars.org/node/3206#comment-21019

Please file bugs on:
http://code.google.com/p/hedgewars/issues/list
(check for existing reports first!)

Try testing new features and utilities/weapons. Try to come up with unanticipated behaviour combinations.

Thanks!

p.s. - for the hat creators.
http://hedgewars.googlecode.com/hg/misc/hats_js_anim.xhtml

Is the current list of hats.
Hats on:
http://m8y.org/tmp/newhats/hats_js_anim.xhtml
that have red squares around them are ones that have pixel errors. Most of them it is subtle. Try changing to a light coloured or dark coloured theme. Some it is pretty clear.
Hopefully someone will fix them so they can be included. Otherwise, they will probably end up in a content pack on:
http://hedgewars.org/content.html