Adventure cartridge – Scott Adams adventures
https://www.mocagh.org/loadpage.php?getcompany=ai&npp=25&whatsnew=0&start=0&series=TI-99%2F4A+Adventures+Series has a nice list of the games available for this cartridge. You need a cassette player/cable or disk system to load the games with the adventure module. No other expansion is required it works fine on stock console.
Adventure Games:
- Adventure #0 – Special Sampler (1979) (Adventureland demo)[4]
- Adventure #1 – Adventureland (1978)
- Adventure #2 – Pirate Adventure (1979)
- Adventure #3 – Secret Mission (1979)
- Adventure #4 – Voodoo Castle (1979)
- Adventure #5 – The Count (1979)
- Adventure #6 – Strange Odyssey (1979)
- Adventure #7 – Mystery Fun House (1979)
- Adventure #8 – Pyramid of Doom (1979)
- Adventure #9 – Ghost Town (1980)
- Adventure #10 – Savage Island (1980)
- Adventure #11 – Savage Island Part Two (1981)[5]
- Adventure #12 – Golden Voyage (1981)[6]
- Adventure #13 – Sorcerer of Claymorgue Castle (1984)[7]
- Adventure #14 – Return to Pirate’s Isle (1984)
Others listed: https://intfiction.org/t/list-of-games-in-scott-adams-ti-99-4a-format/49771
Return to Pirate’s Isle
This game is unique as it was only created for the TI-99/4A (officially adventure #14) and it is the first graphical adventure game published for home computers.
Infocom
Infocom officially released the following games for the TI-99/4A
- Zork I
- Zork II
- Zork III
- Enchanter
- Sorceror
- Deadline
- Witness
- Starcross
- Suspended
- Planetfall
- Hitchiker’s Guide to the Galaxy
- Infidel
- Cutthroats
- Sampler
The TI community has released an updated interpreter that supports all of the original games plus additional
- Ballyhoo
- Suspect
- Leather Goddesses of Phobos*
- Spellbreaker
- Seastalker
A recent infocom compatible release was made that includes a TI-99/4A release
Hybernated – 1 https://atariage.com/forums/topic/321529-for-fans-of-old-infocom-games-something-new/