Gameplay mostly. If the graphic supports the gameplay in a good way, then it isn't important how good or technical advanced the graphic is. I currently play Children of Morta on my pc or on my mobile Stardew Valley and both games have more functional than good graphics. Though, if the graphic doesn't support the gameplay then the whole game isn't fun to play. There were a few games which I stopped playing because the graphical side was just awful. Regions of Ruins come into my mind. No idea why people actually like the game. Gameplay and graphics are just pure basic.
Dont forget audio, audio can be and often is as important as graphics.
I deinstalled Goken because the music destroyed the whole ambient.
