Just noticed: "FEB 28, 2014 5:05AM +You can now zoom with the Mouse wheel" But could there be other buttons for zoom in? My mouse wheel doesn't seem to help either.
To pass chapter four (hard): You need to destroy all of the enemies; that includes the spider tanks being produced every turn and the scorpion tank next to the warfactory. What to consider: *the mortar and all of the trucks can destroy a spider tank on open ground in one hit. **the spider tank can usually destroy any of your vehicles except for the annihilator in one hit. *Use the annihilator to tank damage and deal extra damage, you will be able to retreat it and repair it on some occasions. **You need to get at least one ranged unit past all of the blockades to destroy the scorpion tank, preferably the rocket truck since it has longer range.
*Your ranged units are vital for this mission, losing one can mean a restart is needed. *You can sacrifice your other tanks at the end to deal the extra damage needed to destroy all of the enemies.
Tip: You can attack enemies that are inside an infinity rectangle from the outside but they cannot attack back. Use this tactic with the existing rectangles or try to lure enemies into your own one.
Instead of having "you can buy this thing only once," there should be something less obtrusive. For example, button could grey out or become highlighted and have "acquired" on it.
 "Idle Planet"){kind=icon}
 "Battalion: Vengeance"){kind=icon}
 "New Game"){kind=icon}
 "Defender's Quest (lengthy!) Demo"){kind=icon}
 "Peacefree Tactical Warfare"){kind=icon}
 "IncrediBots 2"){kind=icon}
 "Defence of Portal 2"){kind=icon}
 "DANGEON!"){kind=icon}
 "Me Against The Mutants"){kind=icon}
 "Tri"){kind=icon}
 "ClueSweeper"){kind=icon}
 "Age Of Wind 2"){kind=icon}
 "Infectonator : World Dominator"){kind=icon}
 "Clicker Heroes"){kind=icon}
 "Idle Village"){kind=icon}
 "Idle Empire 2"){kind=icon}
Try www.tri-game.com ;-)