The hardness of achievements is not the same as the time it takes to get the achievements. If it takes long, but is super easy, then it's at best a medium achievement.
Oh wow, I died at the first underground "mario thomps". The game freaked out, showing me places I haven't seen for a one instance and killing me, then the next I'm dying eternally over and over again in the same place...
Loving the game. But why does my revenue keep jumping up and down without any zombies being added to, or removed from, my army/population? Also no change in sales or upgrades...
At first glance this game looked really plain. After playing some of it, I noticed how cleverly deceptive some of the puzzles are. I really enjoy this game, and hope to beat it some day! 4/5
Bug: Ghost items! Sometime you can hit a balloon that is already bursted, or even pick up money a second time after you already picked it up once. The items you hit or pick up the second time are invisible.
Bug report: I boosted with some parts destroyed (wings? I can't recall which correctly...) The result was boosting in full effect, while speed was basically nothing (vertical speed was affected though, but horisontal speed seemed nearly minimal, if not negative!)
 "Mushroom Madness 3"){kind=icon}
 "Realm of the Mad God"){kind=icon}
 "Nelly"){kind=icon}
 "Necronator 2"){kind=icon}
 "Zombies, Inc."){kind=icon}
 "Greedy Ghouls"){kind=icon}
 "Mardi Gras Mayhem"){kind=icon}
 "This is the Only Level 3"){kind=icon}
 "Mushroom Man"){kind=icon}
 "Hordes of Hordes"){kind=icon}
 "Cuboy: Cubeture 2"){kind=icon}
 "Back to Alien Party"){kind=icon}
 "Chuck the Sheep"){kind=icon}
 "All That Matters"){kind=icon}
 "My \"Dear\" Boss"){kind=icon}
 "The Ocean Around Me - Week Two"){kind=icon}
 "Plane Crash 2: Hours to Death"){kind=icon}
 "Hexiom Connect"){kind=icon}
The curse of the point and click perhaps.