Before the cell phone game, there was the graphing calculator game, the inconspicuous high school time-waster that managed to squeeze some fun out of the anemic memory and processing power of Texas Instruments' calculators. Phones quickly grew more powerful than graphing calculators, and offered more storage, and attracted real app developers instead of the hobbyists making calculator games. And phones had color screens.
The classic TI-84 is catching up on that front about a decade too late--Texas Instruments is building a new model, called the TI-84 Plus C Silver Edition, with a color display and a reworked OS to go along with it. We shudder to think what a TI-84 will cost once it catches up on the last 20 years of display evolution--despite a complete lack of innovation over the past two decades, the calculator still costs more than $100.
Graphing calculator apps for smartphones can get the job done for free, these days, though most high school students probably can't have their phones out during trig.
Antiquated as graphing calculators are, it's impressive how many developers have developed low-fi versions of the favorite games for the platform. Ticalc.org hosts a repository of classic games, including translations of Doom and Quake and Bomberman. And people are still making games for them. Text adventure Skyrim? Yep. Castlevania, Mario, Sim City? Those, too.