Yeah, the GBA really should be on top. The other systems just had lower-quality versions of what was available on consoles, but the GBA was the only source of high-quality 2D games for its time. The style pretty much died out during the late '90s and early 2000s, and wouldn't really return until online marketplaces and indie games rose to prominence int he late 2000s and early 2010s, but in the meantime the GBA kept a lot of genres alive.