There are 320 games documented on PixelatedArcade supporting Hi-Res.
Hi-Res is part of the category Display Hardware Supported.
Hi-Res graphics on the Apple II series of computers provided a resolution of 280x192. This allowed 140 columns of color with 6 colors able to be displayed at once. Graphics and text modes could also be mixed, providing 280x160 graphics at the top of the screen along with 4 lines of 40 column text at the bottom of the screen.

Graphics on the Apple II created color in a somewhat unusual way; it relied on composite video artifacting (similar to the IBM CGA cards when connected to a composite display). The actual pixels output by the Apple II were only in black and white; when output was to a color composite monitor or TV, there were two pixels to each colorburst cycle. This allowed four possible colors; it was then possible to shift the alignment of the pixels relative to the colorburst by 90° which provided an additional 2 colors for the total of 6 (actually, the total was 8 however black and white were repeated so the number of unique colors possible was 6). This relatively unique way of generating color created some limitations, one of the most visibly notable ones being that you couldn't set any pixel individually to any color you wanted without potentially affecting neighboring pixels; this led to the color fringing effects that were characteristic of Apple II graphical displays.

On later Apple II systems or upgraded systems, Double Hi-Res graphics were also available which doubled the horizontal resolution allowing up to 16 colors to be displayed at once instead of 6.