Reactions can be added by an administrator just like emoji can.
If you want to see new reactions, all you have to do is suggest them to Randy and convince him it's a good idea.
It's sort of Blade Runner meets H.P. Lovecraft in space.
The second edition is nearing release status.
http://eclipsephase.com/blog
The background information for the first edition is better than most sci-fi novels, especially the gatecrashing stuff.
I believe the quick start rules are free.