I also started with FF 15 A new empire because it was available on playstore. Most FF series are better played with PS. I think the latest versions are more better than earlier series like FF1. This is because of improvements and new features.
If you don't mind snes 8 bit graphics, You can pay money play this game in mobile or you can download it in pirate sites and use an SNES emulator. The characters here dont really have much development but it is a piece of history.
Between playing on mobile devices and console or PC, I would choose the latter because it comes with better graphics than mobile versions of the game. I would only play on mobile when I'm not in reach to game on a console or PC.
I only get to hear about the final fantasy one from some friends that gave me the link to read more about it and I never played the game since to be honest with you, I was not born or even a little when the game was developed. From what I read on the internet, it was one of the series that was quite simple to learn understand and this made the game of final fantasy popular in those days.
FF1 is not exactly the most impressive of the Final Fantasy games. However, it is the beginning of the journey and is just as important as the rest. Its plot is simple and so are its graphics and mechanics. Where it lacks in game quality, it compensates with simplicity and ease of play. The characters look funny too.
Unlike most of you, I got into the Final Fantasy series pretty late. I didn't get a chance to play Final Fantasy I, not because I've never heard of it, but because I never bothered going back and playing it.
You should still give it a try because it is the original Final Fantasy game and it is also one of the main reasons for Final Fantasy’s popularity. It is the first Final Fantasy game that I’ve played when I was a kid. I was hyped by friends to give it a try and I loved it.
Well, since you started with Final Fantasy 6, I think that ordinarily you can assume that the game started from FF 1 before it got to the FF 6 which you were able to start with. This was just like my experience with playing Far Cry games. As I started with FC 5 before drifting back to the previous FC games.