@Annalius Obviously, you don't quite understand the spin mechanics... For example, the spins from AI3 are better than AI2, so, if you kept them, it would be cheap. I understand you are probably thinking, "Why not separate the spins into different categories?" Well TOO BAD because zanzarino doesn't feel like it...
Policeman: "Hey bro! How're you doing?"
Thief: "Great! Uh, just 'withdrawing' some money!"
Policeman: "Alright, you do what you do! Nice outfit by the way. Is it the new trend?"
Thief: "Yeah! Oh, by the way, my lockpick just broke, do you have a spare?"
Policeman: "Sure!"
"Would you like me to talk?"
"You ******* go **** yourself and **** you **** in the **** while you **** your **** in you ****. Yes."
"Ok. I will tell you my battle reports."
"LMFAO"
Here's a grinding guide! First, you must have unlocked Challenge 1: Goblin Madness. You must have unlocked either the Celestial Angel or the Sky Dragon, and Pixies. All other units should be weak. Your hero's can be anything but Popo, as his sight is extremely far, and leaves the castle a lot. Once all your hero's spawn, click assault to send all your units to the enemy castle, but send all your hero's back to your own castle to hold back the goblins while you wait for your Titan(s) to spawn. Once your Titans spawn, send your Pixies and Titan(s) to the castle. Don't worry if your titan takes a VERY long time to reach the castle, that's the point. Send the rest of your units near your castle, to make sure your hero's don't attack the stray goblins that get past or are thrown past your titans. Then, leave your computer, and after an hour or so, you'll win, because your titans eventually reach the enemy castle, but you will have racked up about one million or so! + TO KEEP THIS ALIVE!
Get the Max Mana upgrade for the Undead, and get it to 500, and the mana regeneration upgrade is optional,and get the meteor dmg and the meteor cost upgrade for demons, and you won't need to care about the ninja bosses...
Here's a tip on the bowl. Move your base to the place right after the trench. it wont fit, but you can move it to the left or right a bit, and you can fit it. then, build collectors, and then blasters. then, keep spreading downwards, into the bowl, and put reactors, speeds, storages. then build a relay and move a blaster to the little place that never gets any creepers, just before the bump. then, move your blasters, and mortars. Personally, I think drones just are a waste, but you can get them, just don't forget to use them. Just dont rely on them. then just keep spreading moving your blasters, and connecting them with collectors. then, go layer by layer, until you take over all 3 respawn points, and just take over the totems!