If the game had 3–4 stages, the $4 price would probably feel reasonable. But right now it only has a single stage, and for Android players it feels unfair to be charged while other versions like PC are completely free. A better approach might be to let Android players try it for free first, like a demo, until more content is added. That way, Android users wouldn’t feel disadvantaged, and every platform would be treated more equally. Also, if you do intend to set the price at $4, keeping it consistent across all platforms—not just Android—would be a much fairer and more reasonable solution.