For everybody : try the button "Hint & Tips"... But wait, half of the riders are unlocked by beating the impossible-to-win last level ? Damn. Can't beat MC Shrink neather.
For those who have a Penguin stucked, just blow up the turtle that he is aiming with a bomb, he will redirect to another one. Ho, and some advices : don't get all upgrades for all penguins. I just beat the game with 2 zombies, 1 armored, 1 robot and 1 armored/robot. Upgrade the weakest first, with the most powerfull upgrade you can, and be patient to save some money. The best lvl to farm money is lvl 30.
Good game, love the concept. The difficulty balance is good and there is no need to play 10 times same levels to get the gold and enough xp to manage the next one, but finished already :(
TIP : go for the rainbow, then circus, then auras and lifes. Mana and spells are very usefull for late levels. At first us one turtle for decoy and distribute golems and healers to get through. For the last levels, use : Warlord, Healer, Golem, Goblin * 4, Warlord, Healer, Golem, Goblin*2.
For levels with no magical towers, replace the first warlord with turtle and the second one with goblin. Do not underestimate the warlord : upgraded, he has as many HP than the turtle... And spared damage are better than focused because more easely healed by healers over time. Remember aura doesn't stack !!! +1 if it helped.
Fun game with original concept, but difficulty skyrocket at Unholy Temple... Seriously, 500hp dudes ? Damn, it takes forever to kill them. Plus, need a badge for refunding the debt and it would be great to add more RPG thing (lvl evolution, caracteristics...) than only bonus equipement.
Play normal to lvl 12-15, until you can buy the red spread laser and lvl 3 shield. Then go farm lvl 29 and save up to buy the last weapon. Then beat the game =)