Heed the warning from the red planet, Earthlings! The Martians are about to strike our beloved planet to take our single most valuable resource: cows! Protect Barney's "ladies" in this colorful and whimsical tower defense game! - Full Story Mode (46 levels over 4 seasons), plus 18 bonus challenges! - two game modes: Veteran mode for experienced players, and normal mode for beginners to the tower defence genre. - Intense action! Grab your Zapper to attack the Martians and overpower your machines! - 20 wacky machines, from the classic defense tower to the Helicowpter! - Over 20 quirky Martians, from the Metalhead to the Mad Scientist to the Ninja! - 25 Achievements! - Cows! <3 - Talking outhouse! (wait, what?!)
An excellent tower defense title. Adds a nice active element in the form of the ray gun, which you can use to directly attack Martians, or to temporarily power-up your machines. It nails the cartoon look it's shooting for, and has fun animations, but loses points for being locked to a 4:3 ratio.
This game is heavily influenced by Plants vs. Zombies, with a few different mechanics and a more standard tower defense path structure. If you liked that game, "Beware Planet Earth!" is a natural fit, and I highly recommend it.