Games like Nightmare

Tree of Savior is a Korean MMORPG game.

Orake is a new 2D MMORPG, In Orake you can party up with your friends or make a clan. You can play capture the flag, engage in clan fights, boss fights, explore caves, and much more!

Fantasy Tales Online is a retro MMORPG where you must form parties, collect gear, fight through dungeons and defeat bosses. Featuring puzzles, a rich item system and complex encounters. This isn’t your run-of-the-mill grindfest MMO title!

"New World is a massively multiplayer role-playing game, enabling 2 or more players to cooperate in a vast, open-world setting. Forge your path as you reclaim a curse-infested land, building civilizations and battling supernatural threats. Rich social features and emergent gameplay offer a dynamic, ever-evolving experience."

Kings and Heroes is a fantasy open-world RPG featuring single-player, co-op, and massively multiplayer modes, allowing up to 8 players to explore dungeons and a vibrant town. Choose from 6 races and 5 distinct classes, customize characters, and engage in ingenious gameplay with excellent graphics. However, it suffers from poor optimization, frequent bugs, and heavy grinding.

AdventureQuest 3D is a free-to-play cross-platform MMORPG that allows you to explore an ever-expanding world with thousands of other players. Choose from various classes, battle monsters, complete quests, and participate in seasonal events. The game offers real-time combat, player vs. player modes, and the ability to customize and decorate your own home.

"Bless Online is a free-to-play MMORPG set in a sprawling fantasy world. Choose from several races and classes, and embark on a vast, open-world adventure filled with quests, dungeon raids, and PvP battles. Experience breathtaking graphics and immersive storytelling in this expansive online gaming experience."

"Legends of Aria" is a sandbox-style MMORPG that offers a player-driven economy and dynamic world. Players can create their own adventures, choose from various skills and abilities, and interact with others in a persistent online world. The game features a classless system, allowing players to customize their characters to fit their playstyle. However, be aware that the game has faced criticism for its performance and buggy nature.

"Gloria Victis is a medieval MMORPG with a focus on non-target combat and large scale PVP. Explore a vast open world and choose your path, be it a knight, archer, blacksmith, merchant, or any other of the many available professions. Join the battle for territory and fight in epic wars, tournaments, and castle sieges."

Nin Online is a ninja-themed MMORPG inspired by classic 2000s anime and old-school MMORPGs, offering a hardcore experience with open world PvP. Players can join one of three villages or become a rogue ninja, engaging in both safe zones for training and war zones for intense PvP battles. The game features deep character customization, clan systems, and a focus on skill-based progression without pay-to-win mechanics.