Oh and to add, I am almost there with max upgrades. I am beginning to suspect the game devs put in the final challenge ( epic mode ) as an unbeatable level.
I've completed all levels and challenges in Epic mode. Except the final challenge. Anybody cleared it yet?
For those who haven't tried, here's what happens: A humongous white ape with an unbelievable amount of hitpoints appears. It is so large you can only see its pixelated legs. He appears almost immediately from game start and charges at your castle. There is no time to even wait and store up mana for shield. Even if you do, (actually you do get time for one shield), your castle is not shielded. Three shots from the white ape (Yeti?) and the castle is gone.
Folks! Play this at ArmorGames.com, You see Fort Tran here as an exclusion zone and you can't travel there. But they enabled it on their site. It's a reward before you finally decide to head to UC. Fort Tran has an army base and weapons depot, so you will get a miniMPG and an RPG! The minMPG has 200 rounds of continuous fire, so just single-click mouse and relax and watch them DIE !
The trick is to rescue survivors and help them stay alive. Equip them fairly and distribute your fire power.
Once you have 3 or 4 survivors, the zombies can hardly reach the barricade.
Do not underestimate the compound bow. It has great stopping power, especially with head shots. Single fire but quick reload, so you can get in 3-4 arrows into the fastest and hardiest of zombies and kill them before they get to the barricade. Landmines right at the barricade also helps save your survivors in case one of the weapon-wielding undead get too close.