You might think these games are obsolete. You would be wrong. There is a growing "demake" movement where modern indie developers intentionally create games in the 320x240 style. Furthermore:
In the late 1990s and early 2000s, mobile phones began to transcend their primary function as communication devices, evolving into multifaceted tools for entertainment, among other uses. The introduction of Java-based mobile phones enabled the development and distribution of simple games that could run on a wide range of devices. These games were typically small, both in terms of file size and graphical complexity, with 320x240 pixels being a standard screen resolution. 320x240 size games wwwwapnextcom