A game with no limit: Hours and hours of fun...
From Solo Game you can play against fiendish A.I. characters, any add-on level, completed campaign scenarios and also a trillion of randomly generated games. Solo Game calls the Custom Game interface which allows to alter some game factors, like choosing your HQ location, changing your camp colours, selecting characters face, playing with or without character ranks.
Interface overview: By the numbers
Minimap: At start it's a black
hole so it's where to click first to load an game level. Headquaters
locations are spotted on the minimap with a square next to their
city name. A little flag at your own colour shows your current
HQ location. Nota Bene: the minimap will look different in the game because in game it is centered on your HQ, so here your HQ might look close to an edge but in game your HQ will be full center. Anyway the point is that map edges don't exist in A.R.S.E.N.A.L since map edges are linked to each other.
Monitors: For each city location
on the minimap is corresponding a TV screen (monitor) on
the main monitors rack, each screen have their corresponding city
names indicated at the top of the screen (or at the bottom for
the 2nd row). You can change your player location simply by clicking
in the next monitor that bears a city name then you will see your
flag moving in the minimap to the new location.
Xed monitors: The big "X"
on a screen indicates this location is not available. If you move
you player to an Xed monitor you will not be able to start the
game.
Select
Computer Players:
Once you have chosen your player location you need to select at
least one computer player to start the game. The number of computer
players depends on the number of city available. You activate/desactivate
computer players by simply clicking a valid number on the computer
players panel. Invalid numbers are Xed, you can't click on those
anyway. The face appearing in the screen is the predefined character
for the corresponding HQ location and coloured flag appearing
on minimap.
Play
With Rank option:
By toggling this option, you are choosing whether you characters
ranks will be taken in account or not. This is an important issue
for the game since ranked players start the game with a group
of veteran units whose number and strength increase with the rank.
Suppose you are a Corporal and your opponent is a Colonel, he
will have much more stronger units than you from the beginning,
then you might face the consequences of getting your base rushed
and die within minutes (especially if camps are close to each
other). 
Change
Computer Characters:
Once you have turned a computer player on, you will see the predifined
character for that map location, but you can change this by simply
clicking the '+' and '-' buttons on each side of the character's
face. This is an important issue for the game since each characters
have different attitudes, there are bad guys and good guys out
there, this is how world goes! To find out who are the good guys
and who are the bad guys just have a look at their reputation
displayed beneath their name. Good reputations are Scout, Sherrif,
Governor, Commander and Hero, the bad reputations are Youngster,
Gangster, Terrorist, Dictator and Monster. Because the bad guys
tend to declare war on other players while the good guys are used
to defend the peace you will increase the game difficulty by adding
more bad guys and less good guys. Doing the contrary will make
the game easier, but if you select no bad guy there might be no
war at all except if you decide to declare war on others because
you are yourself a bad guy.
Changing
your colours:
This is the colour you like to wear out in your base, it's every
where, on your flag, units, buildings, even the camouflage paintings
use your favorite coulour. If you get tired of your usual battleship
grey you can change for a shiny orange or a jungle green. An Xed
colour button means this colour is already attached to an other
computer player. To pick this colour you need first to disactivate
the computer player then the colour button will become available.
Generate
a Random Game:
By simply clicking this button, you will access to the Random
Game Generator (see below). 
Start
the game!:
By simply clicking 'Start' the game will start! This button is
enabled if there are at least 2 players present at valid city
locations.