It's easy when you get it going (*wink wink* pick a prefecture that has undead soldiers, you get 3 free fighters each turn. helps a LOT in the beginning, Aomori for example)
The game is quite easy if you study the protectopedia for 5min and play the first 2 parts of the series too. A bit too easy/short in my opinion. I like the series and this one has some nice elements but it lacks a few harder battles. Even the last ones can be done with units of a single 1 element.
Original by Calyad;
Walkthrough! Part 2/3 STEP 6: Upgrade the number of missiles a few times, until it would cost less to buy a laser tower. STEP 7: Buy a laser tower. STEP 8: Upgrade missile # to max. STEP 9: Alternate upgrades for rate of fire between missile tower and laser tower until they are maxed. (Maxed speed laser is amazing!) STEP 10: Sell the top quake tower and buy a laser tower. STEP 11: Max out rate of fire for all towers. Speed trumps damage. STEP 10: Max out damage for all towers. STEP 12: Getcherself an orbital laser and a quake gun for the trucks. STEP 13: Upgrade all guns to max, while accumulating repairmen. STEP 14: Victory!
Bumping the walkthrough by Calyad, originally posted at page 25
Calyad Nov. 08, 2008
Walkthrough! Part 1/3 (Thanks to someone earlier who got me started on the right path, whose name escapes me.) Don't worry about days, just buy the next step whenever you have money enough to do so. Hints are at the end. STEP 1: Buy one gunman. (Just one.) STEP 2: Buy a combat shotgun for $2k. It will be your friend until about day 30, when you get an orbital laser. STEP 3: Buy a quake machine, stick it in the top slot. Never upgrade it, you will sell it later. STEP 4: Buy a repairman. STEP 5: Buy a missile launcher, put it in the middle slot. This tower will be here forever.