You need an external keyboard with your device, simple Bluetooth one should work fine.
I haven't tested this with a gamepad for Android yet, so I couldn't say if it will work. I'll see about getting myself an Android gamepad before next release so I can at least test it out with one.
This game uses a lot of inputs so I immediately gave up in the idea of trying to make on screen buttons.
I'll be putting a splash screen at the start of the game in the next version, to let players know they need extra hardware to play even on Android.