Yes, another Tower Defense game.
Four Days is a grid-based game, with your enemies travelling across the grid from point A to point B, and it’s up to you to place your defenses in the right spots to stop them before they make it there. You’ll have access to a wide variety of upgradeable turrets, including flame, rocket and mortar. Each turret costs money to build and upgrade, which you will receive from each enemy that you kill. There are 20 different enemy types (both land and air), which come in waves, with each level having a specific amount of waves that you need to survive in order to complete it.
Since the levels can last over 50 waves, one of the features that I really liked is the ability to increase the game speed. Once you have a good amount of turrets in place you can speed things up and watch as your turrets take care of business without you having to sit through the final waves on normal speed. Each wave isn’t terribly long, even on normal speed, but it’s still a nice option to have.
It may not have the same level of polish that you would expect to see from a big name developer, but Tower Defense fans looking for a new mobile game should still really enjoy Four Days: World Defense, and you can’t really argue with that fact that it’s free.