You couldn't call Dojo Slash complex or anything like it. In fact, it's deceptively simple. You only ever have to worry about one kind of tap, but it's multi-faceted. Despite the simplistic controls, there's still so much going on that you'll be hooked for a good, long while after your first couple of moves.
You play a ninja who slashes through the competition as you tap the screen and hold to walk. You can use constant tapping in order to move, and then use a string of upgrades in order to give yourself an edge against the green-clad ninjas who stand in your way. You go as long as you possibly can, as continual waves of ninjas saunter up to you and make several attempts on your life. Make sure you slash hard and with haste to beat them at their own game. Each kill nets you an abundance of experience, and you can use it to upgrade yourself tremendously.
The replay value that's here comes in the form of the random variety of upgrades you'll end up applying since when you die, you don't take the upgrades you had previously with you when you go. You're relegated to in-game currency for that sort of progression, a la Rogue Legacy, but that sort of thing is frustrating given the fact that you're forced to keep replaying over and over without any help after you've worked so hard to get it.
This is a fantastic throwback of a game with excellent pixel art and even a silly DOS-esque start-up screen at the beginning of the game. It's fun for on the go play in bite-sized chunks, or for long-time sessions. If you like ninjas and simple gameplay, there's plenty for you here!