Old PS2 controller connect to it directly using GPIOs + i2c 128x64 OLED + Adafruit's 500mAh power boost + 1 cell 850mAh LiPo battery, 1 NPN transistor and 2-3 resistors is all you need to make WiFi joystick which can be coded for in Python. And with it - options are now endless...
BTW It currently serves as client for our PiWars rovers sending high level messages to them through WiFi over MQTT...
Con: it talkes 15s to boot up
Pro: everything else! I must have 4-5 of those more in my parts stash...