Ah, Front Mission, a series I hold very close to my heart, to be honest. I'm really happy the remakes are faithful, for one. Using your own example, I do like Gun Hazard, but if the series became that, I would be outraged; there is no problem with experimenting, but don't expect success by radically changing a formula while offering none of what a franchise was known for previously.
There are problems both ways. Stick with the same formula over and over and you risk stagnation, rendering sequels pointless from a gameplay perspective and useful only from a monetary perspective.
I'm not saying "turn FM into Armored Core" (which they
tried, mind you, and failed miserably), however it's vital that, when presenting changes to something it's important to ask "Is this change good?" and more importantly, "Is this change necessary?"
And for the record, it IS possible to completely change most things while maintaining the spirit of the original. Speaking of Armored Core, the series just did that with AC VI. Hell, that series is an amalgamation of changes and experiments, all 16 games.
As long as you're not doing it cynically to pursue modern trends and have a vision, I think you can do great things.
And a personal opinion regarding RPGs, Final Fantasy in particular: I've seen people complain the new games have become a blend of Kingdom Hearts and DMC.
I welcome that. The more FF becomes KH the more I want to love it. The reason is, I never found the original turn based system of older FF games to be interesting to begin with. I know a lot of people love it, but when compared to other stuff in the genre, well, I'll pass.
Sphere Grid is still rad though, and damn you Square for patenting that shit.