Ecco Jr. is a bit of an oddity -- not entirely a canon game (unless you consider it happening during Ecco's childhood,) but it is a fun addition to the franchise. There are two versions of Ecco Jr.: the Mega Drive game, which saw a physical release in Australia and the US, and then the Sega Pico release which was titled Ecco Jr. and the Great Ocean Treasure Hunt! (or: 右脳開発シリーズ2 Ecco Jr. / Right Brain Development Series 2 Ecco Jr.). Both games are classed as edutainment, with a focus on exploration first and foremost.
Japan did see Ecco Jr. on the Mega Drive, but only through a download via the Sega Channel during August of 1995, so no physical carts exist.
If you'd like to find a specific game quickly, please utilise the code issued by the game's name in the index by searching for it with ctrl+f in your browser.
Index:
[PI01] Ecco Jr. And The Great Ocean Treasure Hunt [NTSC]
Title: Ecco Jr. And The Great Ocean Treasure Hunt [PI01]
Media: Cartridge
System: Pico
Catalogue: 670-5287
Released: 08/1994
Region: NTSC
Scans: Box Front | Box Back | Cartridge | Game 1 | Game 2 | Game 3 | Game 4 | Game 5
Information:
Fill me!