ZombieBucket is a puzzle game that suffers from a very specific frustration-related flaw; It's lack of precision. It's a bit like playing Tetris, but your blocks are controlled by physics instead of always falling the same way. "Matching three" isn't exactly revolutionary here and the addition of timer-based energy system, daily bonuses and the ability to buy and upgrade your buckets isn't exactly what improves the core gameplay for me.
The game requires you to match zombies of the same color to destroy them. Zombies periodically fall into your bucket. When they overflow, you lose. Simple enough! But you have to connect zombies that touch each other, and sometimes this is really vague. The zombies aren't well-placed on a grid, they just fall in weird angles and move along using the laws of physic to guide where they go. This means that when you're matching them, maybe one will move in a way that breaks your connection and you have to re-do it. This make ZB lack the predictability of a puzzle game that - in my opinion - is vital for a non-frustrating experience.
When you kill zombies, you get blood which turns into brains. You also get brains from achievements. These brains are the premium currency of ZB, used to refill your energy, upgrade your bucket or buy one-use items that clear zombies for you. Just buy 1 million brains for 7 bucks, then you can buy all the smart bombs you'll ever need to win forever, for instance! The bucket upgrade system is okay, but it costs a bit too much for a casual player to unlock everything, especially with the energy system.
Some zombies have power-ups on them, like bombs, lasers and other things, and that spices the game up a little, but it also hurts the puzzle aspect. You're not playing crafted levels where you're trying to clear the bucket without having it flow up, you're just matching things as fast as you can and hope for the best. That didn't connect with me at all. ZombieBucket isn't bad, but I felt it was too frustrating and the progression treadmill didn't appeal to me, so I dropped it.