My biggest issue with this game is not the grinding, although that is annoying, but the nature of the random power-ups collected in a level. As each power-up is based of a type of attack, they also suffering the associated penalties to a specific bloon type. This means I often miss a lot of bloons simply because all my attacks suddenly become what they are resistant to. Unless I get the Sun God power-up I am in serious trouble, especially on the later levels. When there is a lot on screen I sometimes can not see the power-up so I do not know if I should avoid it.
Changing the damage formula has made it impossible to do anything in the battle arena. I used to be hitting 500s 9 times out of 10. Now all I can hit are 1s. This means that my combo does not increase and I can not knockback any monsters which results in me dying quickly and often.
I've notived a very odd bug in the battle arena in night forest. Sometimes when I'm hitting an enemy my combo instantly jumps by about 10. I am only using the basic attack.