The number of stars available in the game increased from the original 120 Stars from Super Mario 64 (1996) to 150 Stars in Super Mario 64 DS.
The only playable character apart from Mario who was in Super Mario 64 (1996) was Yoshi. When you collected all 120 stars in the original, a cannon opened up in the castle grounds, allowing you to shoot to the castle roof - and meet Yoshi.
This game was a launch title for the Nintendo DS. Super Mario 64 (1996), the game that this is a remake of, was a launch title for the Nintendo 64.
The working title was Super Mario 64x4, as it was originally intended to be a multi-player demo only. There were no plans to make it a full game.
The game was first shown at E3 2004 as Super Mario 64x4. Screenshots showed the four main characters in a large room battling the main enemy, Bowser.