Echoes of Aincrad is listed as Single-player on Steam and Single-Player on the publisher's page. The partner who fights beside you is AI-controlled.
Why the search is confusing
The game's story takes place inside Sword Art Online, a fictional full-dive MMORPG. Towns, trapped players, and party language make the game look like an online RPG, but those are story and presentation elements. The retail game is a solo action RPG.
What you can do instead
- Choose one partner for each quest.
- Change the partner's weapon and skills at an Inn.
- Use Switch Mode to move enemy attention and create an opening.
- Use Free Mode for combined pressure on a target or group.
- Trigger Combination Skills after building enough damage.
How the solo loop feels in practice
You still make party-style decisions, but they are about commands and timing rather than matchmaking. Before a quest, preview the partner's Support Skills and Combination Skills. During the quest, use Switch Mode to split enemy focus, then return to Free Mode when the target is controlled. This gives the game a party rhythm without requiring another player or an online account.
Is an online mode planned?
Do not treat community wishes or speculative posts as a confirmed feature. The current official product information does not list co-op, PvP, cross-play, or an online mode. If Bandai Namco announces a mode later, it should be treated as a new product update rather than assumed from the game's setting.