Is this essentially the same game as on DS?

[Andrew R]

So all wallkthoughs apply? Thank you.

[Melodia]

Yes.

[EckyThump]

In general, yes.
If you're going for 100% completion/acheivements though - one common point of confusion though is a mention of a chest progress check after completing a certain location. Guides for the DS version will put you at 40%, but playing this version will have you at 39% at the same place.

The mismatch is due to the DS version having 16 chests in the 'Dwarven Treasure Room' location, while there are only 15 in other versions, including here on Steam.
(The missing chest contained Echo Herbs, btw)

[AstroMancer5G]

Yes. The biggest difference is with how you get the Onion Knight, since you can't connect with other players on the Steam version. Instead, as soon as you complete 25% of the bestiary with Luneth or Arc leading your party, you get the Mognet message from Topapa that starts the Onion Knight sidequest.