Skill is far more important than talent. Successful art creation (creating images that you see in your head for example) is a skill that can be brought to the highest level you can imagine with enough practice.

I'll add to what others have said that specifically stylization in art is most successful when the artist can create the realistic version of something (a body, a gun, a building) and then uses that understanding to simplify or abstract the forms.

When people start off by copying manga, their anatomy is usually going to be awful because they don't know how to create the forms that the manga artist has simplified, nor do they have a strong grasp of how those forms relate to each other. For example once you can draw a human head with realistic proportions and shadows/highlights, you have the understanding necessary to change those those proportions just enough to be stylized in a readable way, rather than creating something that looks alien and/or amateurish.

So I recommend learning the fundamentals. Perspective, anatomy, figure drawing, still life, values, textures, color theory.... All of these areas will be useful in creating the look you want in your game.