GH2 has an optional 3D graphics mode, but its pretty notably inferior (i.e. uglier) than the 2D one according to most people that play. I run it ASCII so I couldn't say either way.
Difference wise... yeah. Yeeaaaah. They're both using "basically" the same engine, so there's a lot of similarities in a general sense; movement, combat, character progression, menu layout, etc, all pretty much look if not the
same, then bloody close to it.
Key word there is
look, though. GH2 changes quite a bit about how various mechanics work.
Some -- certainly not an exhaustive list -- examples:
- The skill list has been roughly cut in half, for example, by consolidating a lot of skills (e.g. Mecha Gunnery, which dealt with 'small' mecha scale guns, and Mecha Artillery, which dealt with the rest, became jut Mecha Gunnery) or turning some skills into talents (think dnd style perks, only generally a lot more sweeping or specialized than +1 to dodge or something). In general, this change makes things a bit easier on you, though it's harder to get most or all of the skills with one character.
- You can no longer chat NPCs up to improve their opinion of you, that process is determined by other actions and stat/skill/personality combinations. You get a 'ask about rumors' option, which can infodump you with a dozen rumors in one go
- There's hard limitations on how much you can fit onto a single mech limb, unlike GH1 where the only limit is your mecha engineering and knowledge scores (and how much you were willing to reload). There's a talent that loosens that restriction. There's also several new pieces of equipment, like multi-weapon items, transforming mecha, etc.
In general, though, the suggestion is play GH1 first. The experience is still a bit more streamlined and directed than GH2, it's a bit easier to play (No permadeath, where GH2 has a sort of limited lives thing going on that can be influenced by skills and personality), and it's a fair bit more contained. GH's wiki has more information for GH1 than 2, still, which would probably help. Once you've played through GH1 a few times, moving on to GH2 is a lot smoother processes and you get new toys, whereas it can be a bit confusing if you don't already have some idea of how things are going to go down.