Hello.
There is very cute micro handheld (like Sega VMU or Nintendo Pokemon Mini on steroids) called µGame.
It is based on Atmel SAM ARM (ATSAMD21, 48mhz, 32kb ram, 2mb flash, 128x128 LCD, 8bit mono audio). Main developing platform is Python (CircuitPython/MicroPython) but it is ARM so C, C++...