First of all: I love the genre of game you’re going for! There’s not enough old school dungeon crawling nowadays.
And to answer your question: I do not see any immediate issues with Defold for that kind of game.
How do you plan to represent the dungeon? You could use a perspective camera and a 3D world and move on a fixed grid. There’s inspiration to be had with what @d954mas has done: Noname 2.5 Shooter (Open source). You could also use a normal orthographic camera and use wall sections with the correct perspective like in the original games.