i can get it to 1 million and higher, but i got tired, its pretty repeatetive, i see in the ranking, how can they get 90 days or 6000+ kills ,but not get the highest score (i got the highest) but i just got 3000+ kills and 50+ days
heres my trick: REGENERATING TANKS!
deploy a tank (medium heavy) and an mechanic. click the mechanic and repair the tank (wrench sign) then click the tank (tank only without the mechanic) as you move the tank, the mechanic automatically follows repairing the tank. dont worry about the mechanic's life hes practically safe, since the tank is tanking him (pun intended), except of course if the tank is dead and its been hit by a AOE weapons (rocket launchers) TAH-DAH!!! now you got an almost invinsible tank, level up the tank and mechanic for more power, defense and repair
always max your armor and auto repair when fighting a boss. cause theyre cheaters, no matter how powerful your cannon is, that big baloon will bo,bard you with multiple bombs - instant gameover. so your best chance is fire all your support and some freeze ray to take some time, if youve played right, its gonna be destroyed even before it hits (high levels only, max your defense for low levels)
im done with easy medium and hard, now next is impossible which very annoying, i have to finish 3 games, 1 to unlock the 2 and both must have 10,000,000...
magic is the easy way to go: all fire magic and a long-range weapon, is a good combination. most enemies will lose their armors before getting close to you. and some even burned to ashes. avoid over-kill with magic - you can't receive any holy or unholy bonus.
to kill the guardian: (KNIGHT) level 50 - to equip the most powerful shield.
put all your stat to wisdom (for more hp and mp) then try to get the most powerful weapon and shield you can get, how? - go to sparky fields, enter the dungeon and with luck you will get this items in a chest, rinse and repeat (divine shield and god's fury sword, the armor is up to you, knights armor is the only good one).
then buy 20+ L. potions. and your set.
fighting him is easy, get close enough so you wont be hit too much a normal attack, press and hold (attack) and press simultaneously 1 for potion. you got high chance that youll survive, if your position is good.
total chaos!!!! tanks, jeeps, gas trucks, choppers, air bombings, swordsman , swat , robot soldiers. NO GUNS can stop these guys- so orbital defense cannons are your best shot.