Is it possible to create a .war of a project running on Play, so that it can be easily deployed on Amazon? Or is it necessary to install play on the server itself where the app will be run?
I would prefer a .war since I want traffic from all sources to be able to run the app, not just on port 9000.
Read this for play 1.x, http://www.playframework.org/documentation/1.2.5/production and this for 2.x, http://www.playframework.org/documentation/2.0.4/Production
For easier deployment over SSH you may want to look at, https://github.com/nylund/play-deploy/blob/master/documentation/manual/home.textile (disclaimer I wrote the plugin).