hmm, this could be interesting. i don't think it will be anywhere near as popular as xlib was, though, because prizm basic is so much more handicapped than 8X basic, and because people are much more likely to already know or be willing to learn C than they are asm. still, it's nice to see people adding to the available possibilities.
That said, noticing how the program in the first screenshot ran, I think PRIZM BASIC combined with an xLIB-like language would do the job pretty well. As long as the display speed remains around the same level as homescreen stuff, it will probably have something running at half the speed of Lua on the TI-Nspire for 2D games. Also such language might actually be quite popular because when Lua arrived on the TI-Nspire, its popularity outdid C/ASM and when Axe arrived on the 83+, it got more popular than ASM and BASIC. A lot of people might find C too hard to learn or code and might prefer higher level languages.
And yeah the top left game is an xLIB Metroid clone.