For $0.99, it's a great deal. Though I wouldn't have paid more than $10 for it. While it's great that Mac now has a pretty decent FPS for cheap, there are some downsides to MCD.
IMO, the hit marker system is a bit flawed. Seems flaky.
Guns bought for a particular round are lost as soon as you die. Makes sense, right? Well... very few players opt to buy expensive guns because of this. In my matches today, I'd say over 80% of players used the basic pistol or "splurged" on the cheapest SMG. Everyone uses the exact same guns.
No in-game voice or text chat.
But, buy it now for less than one dollar! It's worth it.