I wish any game existed that was made by me.
Start small. Basically think like a writer: starting "a novel" is the worst way to get into writing, you need to start by writing short stories first. People get into indie gaming then decide to make a huge RPG or be-all-end-all space shooter right off the bat. This is the wrong approach for most people. Think about the least-complex games you
can make, then make them all. Each one will have unique challenges, but you learn from each one as you go. Tic Tac Toe. Tetris. Pac Man.
Pong -> Breakout -> Space Invaders -> Galaga -> 1942 -> Raiden -> Touhou is one possible development pathway. All these games can be built off the same growing codebase.
On the Extra Credits podcast (youtube: and recommended viewing for all wannabe game creators) they had a segment with advice for becoming a starting game designer.
Plan out to make one game, in a week. That should include starting, completing and polishing the game, to the point where the game is "done" and you stick it up on itch.io, no matter how simple it is. The point is: it's a
playable thing that you can show to other people. This is how it's done.
Playable prototypes that you brush your hands off and say "well that ones
done, now I'll make another one".
The alternative, and where people get stuck is by starting their "dream project" and never actually finishing it. Those "games" are often never in a "playable" state until much later. Build simple games, focusing on the "game loop" of actions that the player undertakes. Get playable demos out, even if they look like balls. You can always polish up the most promising ones later, but by making tons of prototypes, you can see which ones get the best feedback before expending additional effort on any one of them.