The Z80 can be considered an 8080 clone with enhancements. In a similar way, the Sharp LR35902 is an 8080 clone with enhancements. While it has many of the same enhancements as the Z80, it doesn't have all of them and some of the enhancements are scaled back a bit. For most practical use, the LR35902 can be considered a Z80 with some limitations.

The LR35902 in the Gameboy has direct accesses to the Video RAM. So, it functions as the Gameboy's graphics processor as well as the CPU.