Just clone Final Fantasy 4
In hindsight I was definitely going for some kind of Mother 3 / Paper Mario esque game where the numbers were tight and small but still a lot of strategy that tied into Jam as a morphing character (I could not decide exactly if he ate metal or toys...). I dreamed up multiple systems that RM2k3 could obviously not handle and kept making new battle system ideas whenever I hit a snag. I really should have just made it a standard spank and heal combat and maybe worry about gimmicks later on (that would just have the usual impact as a limit break system or something). I do recall having only 3 characters that were going to persist throughout the game, so the battle animation spriting I think would have been manageable under those constraints. Point is I should have just kept with what the engine was designed for and make innovations in other areas (like animation and charm in the story). If you look at Space Funeral, the author did not give a flying fuck about battle balancing aside from the obvious "make it winnable" aspects and it was just enough to have the protag cry in the winning animation or something. Maybe I should have just cloned Space Funeral.
In my time playing almost every RM game under the sun if the battles feel like filler or a slog, it's not due to the lack of custom systems or innovative design, it's basic balancing, number tuning, and pacing issues. Those can make or break a game. If I value innovation and such, fine but pick a different engine or ditch the high effort art. Pick the right tool for job and make the necessary tradeoffs.
Pick a vision and stick to it
Pick 1 or 2 things and do them really well, disregard all the rest. I remember not even deciding what the story would be. Truth is anything becomes lame the more you spend time on it and replay the intro over and over. With enough iteration you can potentially surprise just about anyone with enough time and thought, but that has a cost. That cost needs to be factored just as much as any other potential time sink. Really I should have just wrote the entire story in a first draft from start to finish, tweak things a bit along the way but actually stick to immovable story points.
Another thing to consider is just make a few sentences of what the game boils down to "A quirky RPG about an eventual uprising started by unlikely heroes." and just never go in a direction that contradicts that statement. When making The Godfather, Francis Ford Coppola merely went back to the word "Family" whenever he was stuck in a writing corner. This isn't some magical spiritual creative thing he was doing, but a way to merely not get off track and lose sight of the goal. It's vague enough to not be too exact, but concrete enough to understand why you wanted to make the thing in the first place.
If your art is cool now, then it's still going to be cool as fuck 10 years later
Well to someone at least. I remember having thoughts if this game was going to be super dated looking by the time I released it, had I gone through completing the game in maybe 5 years (2015 maybe?). I just assumed no one would play a quirky somewhat earthboundy RPG with 2D sprites by then. The future is just completely unknown and it turns out video games have not gone anywhere despite Phone, VR or whatever advancements. I would not trust anyone's prediction (including my own) on what will be or stay relevant in 10-20 years. To this day I'm currently working on a pixel art horror game and I always think "man are people still going to find this endearing by the time I finish this?" but the truth is that indie games aren't really a technology race (or commercial games for that matter, but that's a whole thing). People are starting to worry if there's any point in making art anymore with AI coming around. The takeaway is: don't worry about the world passing you by, because it probably won't. Just do the work, focus on the craft.
Automate the process
There was a lot of learning on how to do art and how to be consistent, or generally just learning how to do animation on my own and having fun with it. But I really should have put a cap on where the attention to detail stops. I don't know if anyone playing the alpha demo notices this but when Jam walks over a plank in the sunken junkyard he goes up by like 1 pixel. I duplicated a charset and shifted him up just for that effect. The game was full of shit like that, but it's not easy to quantify the value of what those add to the game. I still struggle with this to this day, but at some point you need to put in how many maps, encounters, scenes are needed to be done on a spreadsheet. If you can't calculate that, you should do it based on whatever you make for the first chapter or whatever). But also calculate how long it actually took to make stuff and try to figure out how long it's actually going to take to make this thing. Whenever you play a Final Fantasy game, it's always after the first disc or so that the game starts to feel a little rushed and more A to B plotting and less theatrical setpieces. That's due to the development team sitting down and saying "ok we had fun, now how do we make this in a year?"
You have about 70 or so years to live on this planet (optimistically)
Putting your entire self worth in game creation is bad and will only lead to ruin. If a game takes 5 years to make and you spend all your school summers on them I would seriously interrogate if it was actually worth that time. You have maybe about 16 fully fledged games in you if you can even manage. It's worth reevaluating your relationship with making games once in awhile. I would also encourage anyone in their early 20s to actually experience more of the world and daily life simply because expressing things creatively comes more easily when you actually have tangible experiences to pull from. Exposing yourself to different hobbies and activities that aren't just consuming media actually often helps and compliments the creative process. I also realize that I am a different person from 10 years ago, my likes and dislikes have changed. The games I want to make are completely different. But even that state of mind and outlook is fleeting which is a good thing.
Point is you should complete games faster so you can not only get the ideas out of your system but also to enjoy life more in-between.