the laser cannon is so ridiculously overpowered that the game becomes a joke after you get it...just hold the mouse button, point at any enemy, and win.
All you really need is a spy (to save civs and VIPs) and an R-copter (to destroy literally everything while not losing even a fraction of its huge HP) for most missions. Tesla tank can shoot through walls but can't destroy obstacles, severely limiting its use w/o a transport copter.
Also, hitting a wall seems to be more random than skill-based, as your driver will seamlessly make hairpin turns no human could make and then slam head-on into a wall on an easy turn...
Something about this game is horribly imbalanced, and I think it's the Defensive driving style; in a game where a good strategy is to conserve fuel and not take damage and thus not have to take pit stops, your car should not be able to drive better than the other cars AND fly past them on straightaways...on short tracks Defensive style should not be an autowin like it is on every other track
Finally beat mission 20; I ended up using a lot of anti-air/anti-shield lasers, a lot of damage/range boost supports, and several shield supports around the base. built a recycling plant with about 15 waves to go, sold it before 44th wave, helped a lot...good luck
So...on level 20 do you build a ton of anti-ground towers, sell them all and build AA towers for the last few waves, then sell the AA towers you just built for wave 44, then sell the ground towers you JUST built for wave 45? Because those replenishing jammers just shrugged off 20+ cannon towers, with missiles on the next wave...
tips: build a TON of elevators early on: one for every 10 floors below 30, 1 for every 5 or so floors after that. once you get large capacity elevators replace all standard elevators with them. under 30 floors you need one service elevator, over 30 you need two. once you unlock suite, destroy ALL of your small rooms and replace them with suites; no more elevator/cleaning problems, and you'll make much more money. replace many of the suites w/ presidential suites when you get it and the game is easy, you'll make huge profits
Played this game a few times, and I'd say the best class is the WARRIOR. Hard in the beginning, but Rogan doesn't compare to the build with the Rage passives and Murder, which can do 250-300+ damage (and 150+ late in the fight) to any enemy. Warriors easily get 200+ hp, high def, and do 50+ dmg for normal attacks...way better than rogue/mage.
Tip: play as mage, get necromancy skills only. Prioritize the summons and get Swarm Lord. Summon Demon (with Enhanced Summoning) + Swarm Lord will do more damage overall in a battle than all your other attacks combined...we're talking potentially 40-50+ dmg to every enemy every turn while you cast other spells.
Tips on episode 2: on level 2, just let yellow get infected, tower up, build a ton of resource buildings and build several thor towers. On level 5, you need turrets that can turn fast, so build lots of fusion reactors and then a TON of gauss turrets; you'll easily win. On level 6 don't build turrets, just build a fast fusion and get advanced fighters out to kill their fighters. Build extra starports if you need to.
 "Awesome Tanks"){kind=icon}
 "City Siege 3: Jungle Siege"){kind=icon}
 "Rocket Santa"){kind=icon}
 "GrandPrix Management"){kind=icon}
 "Canyon Defense 2"){kind=icon}
 "Theme Hotel"){kind=icon}
 "Legend of the Void"){kind=icon}
 "Obliterate Everything"){kind=icon}