Localization into foreign markets
While localization can be expensive, it can also open up an entirely new market for your game, which has a multiplying effect on your user base. You may want to consider translating your game into other languages, especially if your game does not use many words.
Sometimes localization requires more than just language translation. Games in English can usually be literally translated to mainstream European languages and find success, but countries such as China or Japan can be more difficult. Besides cultural differences, these countries have strong game development industries already, and it can be tough to gain attention. Still, the market is massive and it may be worth the effort.
Despite the high level of effort and possibility of mistakes, expanding into new markets can quickly multiply the number of people who are potentially interested in your project. It is worth a look, especially once you have proven that your game has demand in the marketplace...