Chockosta has recently released a TI-Nspire Lua version of Gravity Guy:
To avoid getting blocked by walls, you need to constantly hit Tab to switch the direction in which you are falling and you can only switch it when you are touching the ground. Touching arrows on the floor increases the game speed and the speed is cumulative (the more you touch arrows, the faster you go, even to Sonic extents).
It can be downloaded
here! Despite the beta status, it includes a lot of levels and some of them are quite challenging.
Enjoy!
(Original discussion topic)