Just got a few games from github which I'm currently trying out but I've also loaded some free market games that I had on my phone that I can recommend (and since they're free I don't mind giving apks to those who ask):
The Moron Test
Search those up to grab descriptions, some of them are available as apks through getjar, others I'm not so sure.
I've also got a series of emulators that are working great on the Vox:
Tiger Arcade (MAME emulator)
Tiger GBA (Game Boy Advance)
Tiger GBC (Game Boy Colour)
Tiger Genesis (Sega Genesis)
Tiger NES (Nintendo)
Tiger SNES (Super Nintendo)
These don't include games, you'll need ROM images of each game you want to play and it's illegal to own ROM images of games you have not paid for. However, assuming you have a huge collection of cartridge games you'll be able to play a lot of great games with your Vox.
I recommend slower paced games, since using the virtual controller on a touch screen is less than ideal, but it's really not too bad on the Vox. Better than on my phone, really.