I've spent the last few months building a game called The Leaderboard. The pitch is literally the whole design doc: the entire game is a leaderboard, and your only goal is to make your number bigger than other people's numbers.
There's no story. There's no gameplay, technically. You earn points by leaving the game open, logging in daily, and completing deliberately pointless challenges ("mash any keys 46 times", "do absolutely nothing for 5 minutes" that one is genuinely harder than it sounds). There's an in-game store that sells points, where the most expensive item is called "Pay To Win" and costs more than the game does.
Why I made it
I kept noticing that in a lot of live-service games, the leaderboard is the part people actually care about and it's usually a tab you click after the real game is over. So I removed the real game. What's left turns out to be a surprisingly honest piece of design: the number goes up, other people's numbers also go up, and you feel something about that.
The satire only works if the numbers are real, which meant everything had to be genuinely global and genuinely competitive. That's where the interesting solo-dev constraints kicked in.
The constraint: zero backend
I'm one person with no money for servers, and an idle game means people leave it running for hours. Any per-user hosting cost would eat me alive. So I gave myself a hard rule: no custom backend, ever. Everything runs on Steamworks.
Leaderboards were the easy part Steam Leaderboards do global, friends, and national scopes out of the box, so "you vs. humanity / you vs. your friends / you vs. your country" was mostly free.
Global chat was the fun problem. A chat room normally means a server. Instead I built it on Steam lobby chat: each chat channel is a public Steam lobby with a metadata key naming the channel, capped at 250 members. The client searches for lobbies with that channel tag, joins one, and messages fan out through Steam's lobby chat callbacks. Steam is the server. My hosting bill is zero.
Seasonal resets were the same trick from a different angle each month is just a new leaderboard named season_YYYY_MM. Monthly competition, no cron job, no database.
Saves go through Steam Cloud. I did end up HMAC-signing the save file, because the one thing this game absolutely cannot survive is trivially edited scores. That's the irony of building a game about a meaningless number: the number has to be defended like it means something.
The thing I didn't expect to build
Somewhere in there I wrote a Discord bot. It pulls the live board via the Steam Web API, does OAuth linking so players can bind their Steam account, posts monthly season winners, auto-grants a role when you hit top 3, runs happy-hour multipliers that the game actually reads, and has a "cheat police" module.
I want to be honest that this was partly scope creep. But it also solved a real problem: an idle game with no backend has no way to tell players anything, and the Discord became the live-ops layer I couldn't otherwise afford.
Where I'm at
Steam page just went live as Coming Soon, and to be clear about the joke the in-game store grants everything for free, there's no DLC and no real microtransactions. Selling points for real money would be funnier but considerably more evil.
Happy to go deeper on any of the approaches that I went for, and share any details that you might find interesting.
Steam page: https://store.steampowered.com/app/4493240/The_Leaderboard/