Pretty easy if you just max out golem, healer, and goblins + spells... Just do golem healer goblin goblin goblin goblin healer goblin goblin goblin goblin healer, disable bogs and bum rush them, you're going to be casting "heal" a lot so be sure to have it maxed ;)
The difficulty curve is pretty bad... First few levels are easy 'cause starting, just remember to ALWAYS aim for the head... Once you get the sniper rifle that + a group weapon (flame thrower works best imho) will last you until you get the flame gun, then flame gun will carry you through the last 2-3 levels... Flame gun is better than the thrower because the range is so much better... Sniper 1 shot kills everything in the head, so it's going to be your weapon of choice when you're not getting swarmed (hold down the left mouse button, if more zombies are spawning than you get off in shots then switch to your AoE, burn a few down, switch back)
Game itself is 4/5, -1 for content that's not unlockable without using kreds, and another -1 for not being able to even see the stats without buying the gems. Overall 2/5, sorry.
Tip to anyone just starting: Get someone high in Agility and Stamina, moreso stamina. My average stamina score was ~ 21, agility around 25... Reaction was up near 70 and speed always between 50-80. So a starting char with high agility + stamina means less time spent training (and $, tho that's not really an issue). I also geared for +stam rather than overall +, but that would be changed obviously if you reach 999 in all the stats.
So after some more playing, at higher levels + higher waves, tri-color gems are in fact not the best... Honestly dual color gems are about 33% cheaper and only 7% weaker. Mix that with the fact dual color gems have higher specials, maximize that benefit with a trap (traps damages get INSANE with yellow gems, 100% chance for 15x damage + 100% chance to hit 8 targets gets retardedly powerful, not to mention mana leach gems in a seperate area to power-fund your mana reserves). Reds are pretty useless later in the game, but chain-hits are absolutely astounding. Yellow gems are your damage, use the others as a "pre-debuff" for your yellow/green combo's.
Going to have to admit... Way too easy as a mage atleast. Terrify + 4 melee companions and you gotta be retarded to die... Last 2 bosses were just me spam clicking with my #1 ability, maybe turning it to #5 when it's not on cooldown and popping rune of damage whenever I had 100 power... Gold with the gambler is a joke too. Just save, follow some simple logic (6/7 go higher, 9/10 go lower, 8 doesn't matter) and you can get 10-20k gold easily. load back up if you hit a really bad luck streak.
Not too bad, but a lil too easy for my tastes. The gas dudes don't go fast enough to really make vertical towers a challange, and in all honesty the survival mode was more of a time waster...
( = Tower that shoots both ways, _ = nothing, <+ or +> = digestion tower facing the way the arrow points). Just set the towers up ,_,,_,,_,<+ and fix as necessary. Add a few eyes in the blanks / replace top block of towers when needed.
Not a bad game, but waaay too easy... Maybe I just happened to choose the right combo (1 Elite Legionaire, 1 Balista, 1 Lonbowman, 1 Elite Priest, 1 of the circle ring thrower dudes) but literally set to attack and AFK'd the final boss =/
Honestly the balance in this game sickens me. Max out your mana reserve + shield = you're unstoppable. Add a couple of maxed out units and that meteor for the imp level and boom... Game over.
for everyone who's saying to AFK at challange 3; You can get your entire team there if you use all melee units. It took me maybe 3 minutes to down him on epic. Don't waste your time.
Sorry... But the game is way too easy. never had to play a single level twice... Had everything upgraded max by the time I got the last character... Just very disapointing :(