Essentially an RPG/tower-defence hybrid.
Old DQ had lo-fi, 2D pixel art; new DQ instead has hand-drawn, 2D illustrations.
The fantasy world of The Shining Lands has gotten notably darker in the time between the games.

All the fun RPG progression is trekking over to the sequel, too.
The rest of us can enjoy the cold slap of deja vu.
The original genre-bender is also stillavailable.

Promised disclosure: Xalavier Nelson Jr. used towrite for RPS.
Hes now a developer on too many games, including Defenders Quest 2.