4/5 7/10, good game.
ez: 99% med: 99% hard: 98% on first attempt, 100% on all difficulties after ~ 6 tries.
The most difficult part to survive is the start.
Suggestion:
Let mobs have different armors against different tower-colors, and increase the wave preview so the player can strategically plan against which wave color to defend.
Keep up the good work!