SEGA Genesis:
After Burner II
Alien Soldier
Atomic Runner
Bonanza Bros.
ClayFighter
Crusader of Centy
Desert Strike: Return to the Gulf
Earthworm Jim 2
Elemental Master
Fatal Fury 2
Gain Ground
Golden Axe II
Granada
Hellfire
Herzog Zwei
Lightening Force: Quest for the Darkstar
Midnight Resistance
OutRun
OutRunners
Phantasy Star II
Populous
RAINBOW ISLANDS EXTRA
Ranger-X
Ristar
ROLLING THUNDER 2
Shadow Dancer: The Secret of Shinobi
Shining Force II
Shining in the Darkness
Sonic 3D Blast
SPLATTERHOUSE 2
Streets of Rage 3
Super Hang-On
SUPER STREET FIGHTER II THE NEW CHALLENGERS
The Ooze
The Revenge of Shinobi
ToeJam & Earl in Panic on Funkotron
Truxton
VectorMan 2
Viewpoint
Virtua Racing
Warsong
SEGA CD:
Ecco the Dolphin (CD Ver.)
Ecco: The Tides of Time (CD Ver.)
Final Fight CD
Mansion of Hidden Souls
NIGHT STRIKER
Night Trap
Robo Aleste
Sewer Shark
Shining Force CD
SILPHEED
Sonic The Hedgehog CD
THE NINJAWARRIORS
Bonus Games:
Devi & Pii
Fantasy Zone
Space Harrier II (+Space Harrier)
Spatter
Star Mobile
Super Locomotive
VS Puyo Puyo Sun
The only major disappointments for me are it looks like Popful Mail and the two Lunar games are exclusive to the Japanese version of the Mini 2, but the overall lineup for the international version of the mini console is still good. One major standout for me personally is Crusader of Centy, a Zelda styled top-down action-adventure game originally published by Atlus that has probably some of the best visuals on the console and has never seen an official re-release until now. The inclusion of Night Trap is also kinda amusing to me as I imagine its main reason for being included is to cash in on the hype surrounding its legacy of being used in the Supreme Court hearings alongside Mortal Kombat that lead to the ESRB to be established. Also on a personal note, man I remember renting Desert Strike way back when and enjoying it, but never asked my parents to buy it, so it'll be cool to play it again.
For those wondering about the "bonus games" :
The majority of them are games that were in development for the Genesis but cancelled before release, so these are basically pieces of lost media finally seeing an official release (those being Fantasy Zone, Devil and Pii, Star Mobile, and Spatter), Space Harrier 2 is actually a remastered version which is supposed to eliminate much of the choppiness of the 1989 original and play more like the original Space Harrier arcade game, Super Locomotive is an arcade game finally seeing a home release for the first time in 40 years, and VS Puyo Puyo Sun is actually based on a Puyo Puyo game that was on the Saturn and N64.