Grumpy Grognard
Inn Between Worlds
Might have some issues with balancing the different eras as well as the character's skill set.... this kind of absolute clusterfuck of a setting was rare ...
I think it could be done well - time travel as allows for a lot of freedom, but I suspect you'd need a unifying aesthetic and a decent plot, and a bloody good writer to keep the setting scope in check and make it sing.
For example, if you start in the past and have skills for swords and spears, how will the character get to a viable guns skill when he finally hits the modern age?
Great points.
Mechanically, I'd say a combat system designed with melee and ranged combat balance at its core can negate the need for a viable guns skill - or at least create a dynamic where melee is still viable when facing powerful ranged enemies.
On the flip-side: time travel! What if you could, for the right 'price', access a wormhole to a WW2 commando training camp, for example?
On the flip-flop-side: what if ammunition is rare?
(etc)
Is there a way to prevent the Navarro type thing from happening (i.e., the savvy player beelines to the future to get his ray guns then zip back to the past for a banging good time)? How will you balance a sword with a gun, or will you not bother? Would the player be able to grab a M1 tank and drive it back to the Stone Age, because that would cause all sorts of hilarity...
Time travel shenanigans is a lot of fun, but unless it is a relatively simplistic game like U2 where there is almost zero environmental reactivity, it is going to be a LOT of work in the background to ensure there isn't all sorts of lulz of the wrong sort.
You can prevent all those things of course - but it might be more fun to let it happen, and see how well the systems hold up =)
I think of it as a 'what is the cost of time travel' and 'how can/do I use it' kind of problem, really - if you can jump a howitzer into medieval times, the cost / consequences should be significant.
https://youtu.be/H6yzRt2Y_10?t=36