Games like Diskette Dungeon
Games like Diskette Dungeon include Hades, Hades II, Mortal Sin, Slasher's Keep, and Delver. We matched them by the tags players give Diskette Dungeon on Steam (First-Person, Action Roguelike, Dungeon Crawler, Hack and Slash, and RPG): closest matches first, and among equally close ones the better-known games.

Hades
Shared: Action Roguelike · Hack and Slash · Roguelite

Hades II
Shared: Hack and Slash · Action Roguelike · Roguelite

Mortal Sin
Shared: First-Person · Action Roguelike · Dungeon Crawler

Slasher's Keep
Shared: Action Roguelike · First-Person · Dungeon Crawler

Delver
Shared: First-Person · Dungeon Crawler · Action Roguelike

Gunfire Reborn
Shared: Roguelite · Roguelike · Action Roguelike

The Binding of Isaac: Rebirth
Shared: Action Roguelike · Indie · Dungeon Crawler

Moonlighter
Shared: Hack and Slash · Dungeon Crawler · Action Roguelike

Vampire Survivors
Shared: Action Roguelike · Roguelite · Indie

Children of Morta
Shared: Hack and Slash · Action Roguelike · Roguelike

UnderMine
Shared: Action Roguelike · Dungeon Crawler · Roguelite

Heroes of Hammerwatch II
Shared: Action Roguelike · RPG · Dungeon Crawler

Death Must Die
Shared: Action Roguelike · RPG · Roguelite

Megabonk
Shared: Action Roguelike · Indie · Roguelite

Skul: The Hero Slayer
Shared: Action Roguelike · Indie · Roguelite

Garden of Witches
Shared: Action Roguelike · Hack and Slash · Roguelite

Wizard of Legend
Shared: Action Roguelike · Dungeon Crawler · Roguelike

Soulstone Survivors
Shared: Action Roguelike · Roguelite · RPG

Halls of Torment
Shared: Action Roguelike · Roguelite · RPG

Brotato
Shared: Action Roguelike · Roguelike · Singleplayer

Ziggurat
Shared: Action Roguelike · First-Person · Roguelite

SULFUR
Shared: Action Roguelike · Dungeon Crawler · Roguelite

Dreamscaper
Shared: Action Roguelike · Dungeon Crawler · Roguelite

Lost Castle
Shared: Action Roguelike · Dungeon Crawler · Hack and Slash