You should be able to select a group of minions and have them attack an enemy rather than all the minions attacking one for when there are enemies coming from more than one direction.
Take over Echigo and hire a bunch of the units from there. They're 5000 each, but their dodge percentage makes them worth it. + this comment so others can see it.
what exactly is the point in having two different level 2 upgrades to the arrow launcher when they both end up on the same level 3? I think that it should split up and have 2 options for the rifle and 2 different options for the cannon. Maybe that's just me. Great pirate song, makes the game amazing. 5/5.
The hard badge isn't really that hard to get: the longer you hold down the escape key for the higher you jump. Keep pressing the escape key, holding it down until you reach the other wall. You climb higher much faster this way, although you may hit many more spikes. Eventually a map will spawn that works out for this strategy: this badge requires patience more than anything.
"Be careful of spikes - they're deadly!" After two levels of already dying on spikes, because I thought they were grass, this sign could have been helpful a bit earlier.
There needs to be other upgrades after you've beaten all of the levels, as some of the gold stars are pretty hard to get, and there's nothing to buy with 710 million dollars? I don't think that someone with 710 million dollars would have nothing to buy.
For the skull collecting levels, use mostly health boosting stats, although make sure your strength is okay too, otherwise you will be killed before you can destroy the buildings. Make sure you have the Chicken Wings with the Tornado ability. Keep using the tornado, and pick up all of the skulls that you get from the people. These skulls give you more energy for making tornadoes. While you are launching the tornadoes, also be sure to destroy the buildings behind you, otherwise you will have to go back to destroy them, and you might not have enough health left after. You're welcome in advance :)