The Valhalla spinoff game Assassin's Creed Mirage at the moment, it doesn't seem like any groundbreaking new genres will be coming anytime soon. Even so, there's always hope for future entries.
The Assassin's Creed series has primarily been focused on stealthy action-adventure gameplay. Players have been able to explore open worlds and perform dizzying parkour as they navigate the world around them in search of their targets. Other side features such as crafting and rebuilding various towns have been introduced over time, but the stealth and combat have been the main focus since the series' founding. While there have been some changes over the course of the series - such as a higher emphasis on combat and less on stealth in recent titles - the basic mechanics for both have remained largely the same. Game modes like Assassin's Creed Valhalla's Forgotten Saga have also explored things like roguelike features, but there haven't been whole games devoted to them.
It's difficult to say what genres and alternate elements would be best for Assassin's Creed spinoff games, but there are a few prominent candidates. Their quality may depend on how they're implemented, how different they are from the main games, and how far they take the new elements, but they could all help bring new life to the franchise. Seeing new mechanics and gameplay styles could be exciting, as could new settings that diverge from the realistic worlds that the series has used so far. How likely any of them are to see use is questionable, but hopefully future entries in the Assassin's Creed series will take at least a few new gameplay aspects from other genres.
An XCOM-Like Tactical Assassin's Creed Spinoff Has Potential
A good genre for an Assassin's Creed spinoff could be a tactical RPG similar to XCOM. Using this kind of format could be a refreshing change from the typical combat of Assassin's Creed games, and allow players to utilize a team of assassins instead of just the main character. Being able to position a variety of characters throughout a grid map, use cover to protect the various team , and attack in a turn-based combat system could lend itself well to Assassin's Creed, and can be made especially interesting with the stealth aspects that the series is known for. An exact clone of XCOM may not be the best option, but with certain adaptations, it could be quite exciting.
If Assassin's Creed does make an XCOM-like spinoff, it can look fairly different from the main series games. The big maps that recent Assassin's Creed games have become known for may shrink quite a bit, but they don't need to change completely. An open world could still be used, with the map transitioning to an enclosed area where the combat would take place once it starts. Tactics and strategy may gain more importance, and the different assassins could have distinct roles and abilities to help them eliminate their targets. Some could create distractions, for example, while others move in with a hidden blade or snipe from a rooftop. Marvel's Midnight Suns' card-based gameplay will put a new twist on this formula, which is something AC could implement if it ever went down this route.
Assassin's Creed Could Make A Great High Fantasy Game
Another potentially good spinoff is a high fantasy setting. With the Assassin's Creed series' mythological Isu and supernatural elements throughout, it can already be considered low fantasy, so high fantasy isn't too much of a stretch. Most of these things are portrayed scientifically, however, so an Assassin's Creed game full of actual magic that can't be explained away through advanced technology could still bring a new angle to the series. Something like this may seem far-fetched, but with the magical abilities that Odin wields in the AC Valhalla expansion, Dawn of Ragnarök, this could be more likely than it appears at first glance.
Assassin's Creed Needs A Survival Game
Another good spinoff for the Assassin's Creed series - and perhaps the most likely - is a survival game. Having to manage food, water, and perhaps more advanced options like temperature and shelter can add a greater challenge to the games, and make use of their increasingly-large open worlds. Hunting and animal companions already feature in Assassin's Creed, so the meat players already obtain from wild animals could easily be adapted to fill a hunger bar instead of a health bar. There's also a readily-available premise; the Brotherhood works in the shadows and operates outside the law. If a branch is expelled from its headquarters and hunted down by the Templars, then its could very well be forced to fend for themselves in the wilderness.
An Assassin's Creed game with survival mechanics may not look too different from one in the main series. Crafting may take on a much greater role, and players might be limited to more primitive weapons and armor in the early parts of the game, and to facing off against wild beasts more than humans. This may depend on what premise an Assassin's Creed spinoff game with these elements uses, however. If it takes place in a timeline where Desmond Miles did not prevent the Second Disaster, or some similar event wiped out the modern world, urban survival may be more appropriate and players could control a Desmond Miles or other Assassin stricken with the Bleeding Effect.
