YMMV / Tower Madness

• Demonic Cockroaches: Crittasaurs. These giant alien cockroaches are the fastest unit in the game, and are surprisingly durable for a speedy enemy. The King Mook version of these is even faster, and can take a lot of damage, making it a definite Demonic Cockroach.
  • Flying aliens, especially in later waves, will fly over many of your turrets. While this isn't an issue at the first half of waves (just use an Anti-Air and watch them go down), they will require at least two fully upgraded flak turrets to take down a wave later.
  • Regenerative Aliens are, well, aliens that can regenerate health. While not too hard to kill if slowed, the King Mook version of them can be quite a problem, especially when it regenerates health at a faster rate. You'll definitely be going "Why Won't You Die?" when facing these.
• Game-Breaker: The Flamethrower weapon. At level 2, it burns through enemies, including King Mooks, with relative ease. At level 3, almost nothing survives. To balance it, they come at a high cost, have even higher upgrade costs, have a long purchase time and even longer upgrade times, and you have to buy them online if you want to use them in-game. The game also has ghost aliens that are immune to this weapon.
• That One Boss: Crittasaur Kings!!! Especially in fixed placement levels. In dynamic placement levels, the Flying Alien king fits the bill.
• That One Level: Any level where the aliens attack from all sides of the map. Such as "Giza".
  • The level called "Endurance". If you have the flamethrower and use the right strategy, you'll do just fine without losing a single sheep. Then comes the Boss Rush at the end... AAAAAAAARGH!!! FLYING AND CRITTASAUR ALIEN KINGS!!!
  • Now we have "Sudden Death". You have 1 sheep in the center of the field, and there are 6 places where the aliens spawn, all on the borders of the map. Good luck trying to deal with Death In All Directions...