I played the second one for a few hours for the achievement earlier. Going from that one to this one makes a world of difference. My first try I hit the moon in 6 days and it only took me 3 tries to get under 5 days :).
The key is to get the best run possible on the first day.
if u want multiplayer add name and pass it on. vabubbi,PatrickG,BOMBSHELLMAN, loingelf,Valdonar,saint_skx,Max_Planck,AnAverageGuy,lorddeadman,WhiteshadoW3,Savagehare99,Nagylevi,skaren,mcdonaldjord,Fighterspirit,Ninkov,Skytipper1, residentblue, howisdiscool, narutorules7777, CowBoop,ak1215, Tommyst,wheehoo,curlykyle, Rob_The ,football13,masterfart22,necroscape12, Razzle00,gameman272,Xanadu505, Jmb30150, MorDeCaza,Diegoluna123 ,H2liveshot,***IMORTAL00***,stupedperson2797,Helgrind, Spyguy10 evlpengwin476, Zexionismyhero, Alan0wnzu, OnceWronged, arcticwolf15, skeightmachine
Atron Said it perfectly
"Did the spartans without taking any damage by purchasing an orbital defense cannon, purchasing max ammo and radius upgrades, and then laying waste to my foes. "Then we will fight in the shade," indeed."
I just found an easy way to defeat the final boss easily. There are 423 pages of comments so im not sure its in there. Anyways, the final boss does an attack that deals 4k damage to one member of your party. This attack requires all 100/100 of his mana. Simply use the attack that drains mana and he will be unable to deal this devastating attack.
Now just wear him down until he regains his mana, then do the move again. Simple.
 "Hedgehog Launch"){kind=icon}
 "SAS: Zombie Assault"){kind=icon}
 "Storm the House 3"){kind=icon}
 "Sonny"){kind=icon}