making a game look good isn't only about the assets, it's about putting them together in an interesting way, it's about the UI layout, the VFX and lot of other factors. Like if you look at my game the assets are not insane, but I think the game looks okay because of the post process and the VFX that were really simple to make (took me like 1 hour max). Anyways all that to say, take practical decisions, if you don't have time just ask yourself how to get the best result in that amount of time you have.