I had the luck of owning a TI99/4A as a kid; it had a very rich Basic, with the 16k extension cartridge you even had sprites and a synthesizer. I have made some 2d game stuff with pygame recently, and for me it felt as if I got back to this old machine... (here is this stuff, for the record: https://github.com/MoserMichael/pygamewrap )
It was possible BITD too, but no one thought hard enough about how to do it. There has been a lot of "pushing the hardware" over the last decade. Lots of things that were thought of as "not possible" have been done now. The 99/4A community is very active, and there is a lot more going on than just new games (although that is also a big part of the activity).
I had the luck of owning a TI99/4A as a kid; it had a very rich Basic, with the 16k extension cartridge you even had sprites and a synthesizer. I have made some 2d game stuff with pygame recently, and for me it felt as if I got back to this old machine... (here is this stuff, for the record: https://github.com/MoserMichael/pygamewrap )