Yes you are right. I think if it is easy mode or normal mode, its fair. Because these both modes are meant for everyone.
In the hard mode and very hard mode this is not good. However we have made some balancing in last night update. I hope they will fix it.
The achievements are kind of messed up. I keep getting the X Tower Level 3 achievement over and over. Also, I'm getting the Boulder Tower Level 3 achievement when a Spear Tower hits level 2. :S
I went to click on things in the main menu to see if they gave me achievements (they didn't) and when I went back in all my money was gone but the achievements were still unlocked so I couldn't make any more. :(
 "Swords & Potions 2"){kind=icon}
 "Spectromancer: Gathering of Power"){kind=icon}
 "Arcane Weapon"){kind=icon}
 "Giants and Dwarves TD"){kind=icon}
 "Band Of Heroes"){kind=icon}
 "Lucky Tower 2"){kind=icon}
 "Deep Sea Hunter"){kind=icon}
 "Bloons TD 5"){kind=icon}
 "Blocks"){kind=icon}
 "Relic Of War"){kind=icon}
 "Zombotron 2"){kind=icon}
 "Castaway Island TD"){kind=icon}
 "Ragdoll Achievement"){kind=icon}
 "Kamikaze Pigs"){kind=icon}
 "a Grain of Truth"){kind=icon}
 "Nightmare Runner"){kind=icon}
 "Reprisal"){kind=icon}
Yes you are right. I think if it is easy mode or normal mode, its fair. Because these both modes are meant for everyone. In the hard mode and very hard mode this is not good. However we have made some balancing in last night update. I hope they will fix it.