https://game.watch.impress.co.jp/docs/interview/1277947.html This comes from an interview with Yousuke Okunari from Sega and M2 staff members in a Game Watch article. The interview's in Japanese, but the really interesting stuff can be easily read via Google Translate. The most interesting stuff: - The Game Gear version of Gunstar Heroes originally had a ton of flickering issues. This has been fixed for the GG Micro release, but if you want to play with the original flicker intact, hold down on the D-Pad while selecting the game. - Holding Up on the D-Pad while selecting Gunstar Heroes will play a looping demo of the game that ends with "Coming Soon" text. This was a video demo presumably put together for a toy show that happened to be found when Sega provided M2 with the source binaries for the games on the Micro. - Because some of the main menu multiplayer menu options in Puyo Puyo 2 would be rendered useless on the Micro, the main menu screen was redrawn to account for the two remaining modes, and the character on screen also had a blinking animation added. - The two Last Bible games on the Red Micro have new optional "Easy" modes, experience and money earned are tripled in Last Bible, and doubled in Last Bible Special. These additions were inspired by similar options implemented in the PS2 Complete Collection and Sega Ages Nintendo Switch releases of Phantasy Star. - The cheat codes for Sonic & Tails have been made easier to account for the smaller buttons. For example, the level select code in Sonic & Tails is now pressing, Up, Up, Down, Down on the title screen, and to access the sound test, you press Down, Down, Up, Up. - Likewise with Sonic & Tails, Puyo Puyo 2's cheat codes were also simplified for the same reasons. To change the appearance of Puyos in-game, you simply press and hold the start button and either the 1 or 2 button as the game's opening demo plays. Other random details: - The GG Shinobi was used as a litmus test by M2 to determine whether or not action platformers would be viable on the Micro's tiny screen - The menu music was composed by chibi-tech. The alternate music that plays when returning to the menu after starting a game was composed by Shinichi Sakamoto, composer of the Wonder Boy games. - The screen showing off the open source software used for the Micro's development plays a short looping song based on Greensleeves. This was chosen because the same song was also used for Sega's old UFO catcher machines. - When the battery is about to die, one of six warning screens will display, showing characters from Alex Kidd Fantasy Zone, and Flicky, among others. While you can't exit back to the game when this warning appears, it does allow you to quickly create a save state before the power goes off. For what's essentially a novelty toy that isn't leaving Japan, M2 sure did go above and beyond here, as far as emulation and features are concerned.