Ah i was coming here to warn you about that.
Ill brace for downvotes but if i can light a candle for just one person, that would be fantastic.
A big misconception about the economy of games is that they are content - economically-wise. An example of content is music or movies, think spotify or netflix.
This is absolutely not the case. Economically, games work like software: a handful of games are played for years and represents 98% of the playtime / money.
Treat games like a startup: what will make your game still be played 10 years from now?
Dont think "im gonna do one game and then another". Think "ill make one game". You wouldnt think "ill make a startup and then another and then another" even though you could its not really how youd think about this stuff right. Do the same with games.
One game. One startup. One product. Played for years on end. Diverge from that strategy and chances are you wont have a good life as a game developer like millions before you.
That being said, lets say you want to make a "content game", that is, a clone (your 2d platformer with a nice plot and rpg elements). Nothing wrong with that but just understand that on the long run it wont be sustainable economically, even if you take a lucky jump.
Where do you get this stuff?
I don't think much of the software out there behaves like this either. It might apply somewhat to game or software franchises, though.
For example, LibreOffice has had multiple major releases, but has been around for a bit over 12 years, a bit longer if you include the predecessors. Ubuntu LTS is usually supported for around 5 years, but Ubuntu as a whole has been around for almost 20 years.
Similarly, Counter-Strike was released over 20 years ago, even if there's been multiple separate games over the years. It's more or less the same story for Battlefield and Call of Duty.
That said, that's setting your own goals unrealistically high, since those are the exceptions when compared to any number of unsuccessful games. If you try to compete against games like that, you'll just burn yourself out. Most startups aren't necessarily built for the longevity either, but rather to have a product hit the market within a reasonable time frame and budget.
If you want, make games, fail, iterate, fail some more, iterate some more, maybe eventually succeed. Have a look at some grounded experiences from other folks, for example watch this video titled "How to Survive in Gamedev for Eleven Years Without a Hit": https://www.youtube.com/watch?v=JmwbYl6f11c
Most games are played heavily within the first year, and thereafter not so much. Indeed, game revenues in general are even more front-loaded than movie revenues; for most games, 80% of the game's lifetime revenue is made in the first 6 months of release, which is why DRM is a thing on new games but usually gets removed in a patch a few months after release: to stop piracy during those crucial first few months. (With movies, excluding blockbusters which live or die by their box office, most of the revenue is made after the film leaves theaters from licensing deals and consumer media sales.)
Excluding subscription games like MMOs, only a tiny handful of games continue making substantial amounts of revenue after 6 months. Games like Minecraft, Terraria, and Stardew Valley are the exception, rather than the norm.
Don't let that dissuade you. As a solo developer, you only need a few thousand in sales to make a good living.
I didnt start receiving publishing offers until 13 months after I started development (and notably, when I started adding serious art to the game).
Currently trying get a small project off the ground while working full time at a large company. The goal is to get enough momentum on a project to find a good jumping off point.
The project is a multiplayer adaptation of frogger, where players are competing be the last man standing dashing across roads and rivers. The USP is allowing players to push each other around, this really adds to the competition (you can push people in front of cars, off of logs etc)
The target audience is "skibble.io users" so bored students / employees looking for something to do over zoom. So I'm building it out as a webpage with no login and as quick as possible time to game.
I have some info here https://forums.tigsource.com/index.php?topic=72732.0
And there is an old local-only prototype here https://danslocom.be/gamepages/crossy.html
They all had a day job.
Sometimes game dev related, sometimes not so much. But they all sacrificed a large portion of their free time at least until they started to generate enough money to survive on game dev alone.
In the end, the game is its own thing. It better be fun. It better be enjoyable. Otherwise all the above doesn’t matter.