Artillery comes in several forms;
Mobile light artillery Edit
T1 mobile light artillery is built at T1, which is a useful, and often used unit, and is essential for T1 point defense busting, and can be used even late into the game; due to the low speed of larger units, and its impressive DPS for its cost.
Stationary T2 artillery installation Edit
T2 artillery installations are built are at T2, and are often used as a heavy base defense substitute (en mass), although their high cost and energy consumption means they are often not built until late game.
Mobile heavy artillery Edit
T3 mobile heavy artillery is built at T3, with an medium cost, are often used as base busters, and are very effective at their task. They can also be used in conjunction with a fire base, to provide heavy long range fire support. They are only moderately effective at taking on experimentals, as they have no armor, and are entirely indirect fire units.
Stationary T3 artillery Edit
T3 heavy artillery installation is built at T3, with an immense cost, their immense range, high damage, and relatively high ROF, and a relatively low energy consumption (considering the economy required to build one). After considering this, they are perfect for base busting, have no self defense, and must be defended heavily, although their cost really is a limiting factor when considering whether to build one or not.
The Aeon T3 rapid fire artillery: Salvation, again see the game ender article for more information. Once built, every second it exists, the enemy is worn down yet more. Further ensuring your victory. While not technically an Experimental, its build costs and times make it more expensive than many experimentals.
The Cybran experimental mobile rapid-fire artillery: Scathis, this is also a game ender. It has a really fast ROF and will blow any target area to smithereens with a barrage of shells. The shells haven't got that much damage, but they have a large area of effect.