True, there are several virtual pet games out there for the TI, but this is the first one using chao, the cute virtual pet in the Sonic Adventure/Sonic Advance series.
There are some issues - on the TI-84, which I have, the timer for Treasure Hunt runs way too fast - and you can't do as much with your chao as you can on the GameCube or even the GBA, but it's still a pretty fun game for when you're bored or for Sonic fans. Mirage compatible, too.
It's a bit hard to figure out which buttons do what, and there's no easy way to quit Chao Race or Treasure Hunt without completing the game, even though it says, "Press CLEAR to quit" on Chao Race.
I have never used the "Link Battle" function, so I can not honestly state the rating.
The only error I got from this was a "BREAK" error from when I had to use the ON-break to exit Chao Race and Treasure Hunt.
Good game, but there are some things that need to be worked on.