I find that certain bloons in BTD Battles are OP. Here are my modifications:
Regrow: Round 10
Camo: Round 14
R2: Grouped Reds or spaced Blues
R4: Grouped Blues or Spaced Yellows
R6: Grouped Greens or Spaced Pinks
R8: Grouped Yellows or Spaced Blacks
R10: Grouped Pinks or Spaced Whites
R11: Grouped Whites or Spaced Zebras
R12: Grouped Blacks or spaced Leads
R14: Grouped Zebras or spaced Rainbows
R16: Grouped Leads or single Ceramic
R18: Grouped Rainbows (Costs $500, decrease income by 3) or fast-cooldown Ceramic (Decrease income by 3, cooldown 0.5s)
R20: Grouped Ceramics X 3 (costs $1300, decrease income by 20) or Single MOAB
R24: Fast Cooldown MOAB or single BFB
R28: Fast Cooldown BFB or single ZOMG
R35: Spaced DDTs X 3 (regrow and camo do nothing extra, costs $40000, decrease income by $2500)
Also, I would like to see an option in the 'Select Tower' screen called Pascifist Mode. If both players select it, all sent bloons don't actually appear, so that they can only be used for income generation.