Recently, I'm taking a look in a gameboy game. The game is Metroid II - Return of Samus. Using no$gmb debugging, I was able to find some OAM sets for editting. In 0x4095, I can see OAM for "Press Start" and "Completed" words.

In Gameboy, it seems that 4 bytes are used in OAMs (in GBA, OAM have 6). two bytes allows me to change horizontal/vertical position. one determines the tile used.

In GBA, changing one or more byte, I could change OAM sprite resolution to 16x16, 32x32, etc. But searching in google earlier, It seems that Gameboy can use only 8x8 resolution.

talking about resolution, is there some way to change resolution to 8x8 for 16x8 only by changing one of those 4 bytes at every OAM? or It involves something much more complicated?