A bizarre but brilliant first-person RPG set in the Doom universe. It uses a turn-based grid movement. The 320x240 resolution allows for detailed HUD elements (health, ammo, map) without blocking the 3D view.

A stealth action game optimized for landscape. The 320x240 screen features a "light meter" and a mini-map that allows you to see enemy patrol routes.

You cannot install JAR files on an iPhone or a modern Android phone directly (unless you use J2ME Loader). Here is the setup for the best experience:

If you have exhausted the top 10, look for these niche masterpieces:

A turn-based strategy game similar to Advance Wars. You command Romans, Vikings, and Egyptians. The 320x240 screen is non-negotiable here; lower resolutions make the unit icons indistinguishable.

A cult classic puzzle game. You play an explorer in a grid-based temple avoiding snakes, rolling boulders, and collecting gems. The 320x240 resolution allows for a larger playfield view.

320x240 Java games (J2ME/MIDP) were popular on older mobile phones (Nokia, Sony Ericsson, Samsung) from ~2004-2010. Key characteristics:

This is the tricky part. Do not download from pop-up heavy sites. Use Archive.org (search "Java Game Preservation Project") or Dedomil.net (filter by "320x240").