Graphics don't matter as long as you have a coherent style. Pre-written "story" is not critical to games, and enabling player creativity is something that will be eagerly received. One person really can make a great game all by themselves in a reasonable amount of time.
Amusingly, the only lesson learned by most developers is that people really want block-based worlds. Nah. If you look at Minecraft and Dwarf Fortress as just the beginning of what enabling player creativity in a simulated world can look like, that way lies the future.
The indie road to success is the path not taken by AAA games. There's so much potential for what games can be that hasn't been explored by mainstream publishers, and Minecraft is a superb example of that.
IMO it's quite possible to do well on the app store. Sometimes someone builds a great app, and it does marginally well, but Google or Apple notices it. They recognize that it's an interesting product and will likely at least call you about a job. Which in my book, would be somewhat of a success.