Every "type a prompt, get a game" demo hides the same fact: someone is paying for that generation, every single time, whether the result is good or not. Here is what that bill is actually made of.
The three things you're paying for
Text generation (the plan, the code, the dialogue), image generation (sprites, tiles, portraits), and the compute to run the automated playtest loop that catches what broke. All three are metered by the provider behind them, and none of them get cheaper just because the output was disappointing.
Why retries are the hidden cost
A clean generation that works first try costs one call. A generation that needs three retries because the automated playtest caught a bug costs four, and the player, or the free tier user, never sees the difference, they just see "it worked." Any tool that plays its own build before handing it to you is spending real money on quality control you don't see the bill for.
Why "unlimited generation, one-time payment" doesn't survive contact with reality
The math is simple and unforgiving: fixed revenue, variable cost that scales with usage, equals a business that loses more money the more its best customers use it. Every company that has tried true unlimited generation on a lifetime license has ended up doing one of three things: quietly rate-limiting heavy users, adding a "fair use" clause nobody reads until they hit it, or shutting down. This is not a failure of execution, it's the math working exactly as it should.
The two honest pricing shapes
Either the software is free and generation is metered (you pay for what costs money, nothing else), or everything is bundled into a subscription priced high enough to cover the heaviest users, which means light users subsidize heavy ones. Neither is dishonest. What's dishonest is a price that doesn't map to either shape, because that price is either unsustainable or hiding a catch you'll find later.
What this means if you're evaluating one of these tools
Ask what happens to your access when generation costs go up, because they will, compute pricing moves. A tool that can answer that question specifically has thought about its own economics. A tool that just says "unlimited" hasn't, or is planning to change the deal later. Neither answer is a dealbreaker, but only one of them is honest right now.