You are talking about the Gamebuino Classic. Since that device does solely have 2kB RAM there won't be much higher resolution, which could be handled with that RAM. The Arduboy has a comparable CPU, which managed to get 128x64 pixels out of it (a comparable display might be this one: https://www.adafruit.com/product/938). That is still far off from a finegrained resolution, though.
Hi, i'll make a parachute port on the META. I had done one one the classic, i was doable even resolution was low. On the META, i'll try to use the Hi Res mode (160128) a tuto to use this mode with the current memory has been done, i need just some time to read, try and use it (It's a little more complicated but 160128 / full color is amazing to emulate the old handle games from nintendo as you can let the sprites black and recreat the backgrounds of this games)