A few GB Multicarts...

[taizou]

The only one I can guess at is the "NT9915" one, which was possibly made by NT (Ka Sheng). No idea about the other two.

Doraemon 4 probably is official given that it's in Japanese, most pirate originals are in either Chinese or English, but I don't know of any Doraemon game with that title... does it actually say "4" on the title screen? According to Wikipedia, the official games are:

Game Boy
 Doraemon 2
 Doraemon Kart (Game Boy)
 
Game Boy Color
 Doraemon 2
 Doraemon Kart 2
 Doraemon Kimito Pet no Monogatari
 Doraemon Memories: Nobi Dai no Omoi Izaru Daibouken
 Doraemon no GameBoy de Asobouyo DX10
 Doraemon no Quiz Boy
 Doraemon no Quiz Boy 2
 Doraemon no Study Boy: Gakushuu Kanji Game
 Doraemon no Study Boy: Kanji Yomikaki Master
 Doraemon no Study Boy: Kuku Game
 Doraemon: Aruke Aruke Labyrinth

So it's likely one of those, I guess.

[ClassicGamer]

No, it doesn't. The title screen actually says "10"! There are a bunch of Japanese letters, the Game Boy logo in english, the Doraemon logo in Japanese and a big 10. The copyright says "(C) 1998 Epoch Co. Ltd.
Maybe it's a title screen hack of one of those games? If it is, maybe it can be identified by the game itself? It's just a bunch of minigames, with a short backstory about a guy getting beaten up, possibly to his death, in front of all the playable characters (except for Doraemon, who appears later.)

[taizou]

ah, I guess it's Doraemon no GameBoy de Asobouyo DX10 then, that seems to fit.