I've tried ripped copies of the games you listed on an AtGames handheld before (via the SD card slot), they're definitely Niutai-developed. If a game has a "© ALL RIGHTS RESERVED" notice without actually listing a company, that's your clue that it's a Shenzhen Niutai production. Of note is that most of the sports games have their controls turned on their side, as they were presumably designed for knockoff Wii Remote controllers (appearing on the Sega Genesis Arcade Motion Dual etc).