Barrage is an action game with the only objective, destroy anything that moving. You have an artillery with big canon. No body will attack you. So, just fire your canon to your target, kill and destroy anything in 3 minutes.
From Ubuntu Terminal screen (Applications > Accessories > Terminal), type:
taufanlubis@toshiba:~$ sudo apt-get install barrage
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following NEW packages will be installed:
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 409kB of archives.
After unpacking 2003kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com gutsy/universe barrage 1.0.2-1 [409kB]
Fetched 409kB in 4s (83.3kB/s)
Selecting previously deselected package barrage.
(Reading database … 161741 files and directories currently installed.)
Unpacking barrage (from …/barrage_1.0.2-1_i386.deb) …
Setting up barrage (1.0.2-1) …
How to play?
Open Applications > Games > Barrage
Fire: Left Mouse button.
Reload: Space bar.
Select target: Mouse pointer.