There are 485 games documented on PixelatedArcade supporting OCS/ECS for Amiga.
(View for All Systems)
OCS/ECS is part of the category Display Hardware Supported.

Amiga computers equipped with either the Original Chip Set (OCS) or Enhanced Chip Set (ECS) are capable of displaying graphics with a total palette of 4096 colors. Depending on the graphics mode, the number of colors usable at one time can be either 2, 4, 8, 16, 32, 64, or 4096 colors. There are some limitations when either 64 or 4096 colors are used; 64 colors are achieved via the Extra Half-Brite mode. In this mode, 32 colors can be selected from the overall palette and the remaining 32 colors are the same colors but half as bright. Some early model Amiga 1000's released in the United States don't support this option. 4096 colors at once are achievable in the Hold-and-Modify (HAM) mode. In this mode a pixel can be set to one of 16 colors or it can take the RGB value of the pixel to it's left and modify either the red, green, or blue component. This allowed more colors on the screen than any other home computer at the time, but the unusual technique would typically lead to color fringing artifacts in the image since it could take up to 3 pixels to achieve the desired color. Because of this the HAM mode was most often used for static displays such as splash screens rather than in-game graphics where animation was required.

Several display resolutions are available which will vary depending on if the system is NTSC or PAL. Available options for NTSC are 320x200, 640x200, and 640x400 (interlaced). For PAL, the options are 320x256, 640x256, and 640x512 (interlaced). The hardware was flexible and also allowed somewhat higher resolutions by taking advantage of the overscan area and also allowed modes to be mixed by splitting the screen vertically.

OCS and ECS were followed up by the Amiga Advanced Graphics Architecture (AGA) in 1992 which was available for the CD32, Amiga 1200, and Amiga 4000.