Acquire has connections between some of the games to, particularly between the Way of the Samurai and Shinobido games. I'm pretty sure the fanbase for either one of these series is rather minor, so I'm probably sure nobody else has posted about it.
- Nomi, one of the characters from the first and third WotS games who serves as the instructor to the game mechanics appears in Shinobido: Tales of the Ninja as an unlockable character once you complete the game 100%.
- Zaji, one of the important characters in Shinobido: Way of the Ninja and Tales of the Ninja, appears in WotS3 as a hired ninja in one of the possible storylines of the game.
- Rokkotsu Pass, the location of the first WotS is also present in cutscenes in the original Shinobido as a resting grounds for the Kenobi Clan, one of the three ninja factions in the game. The cutscenes also include cameos from Suzu and Kurikichi, the two characters who run the restaurant during the events of WotS.
Another example of a pretty niche crossover involves the company Falcom and one of their games, Ys vs Sora No Kiseki: Alternative Saga. It dominantly features characters from the Ys series and the Legend of Heroes games, but includes tons of assist characters from many of Falcom's games. I don't even know all of them, but I would not be surprised if all of their games had some cameo in some fashion!
- Nomi, one of the characters from the first and third WotS games who serves as the instructor to the game mechanics appears in Shinobido: Tales of the Ninja as an unlockable character once you complete the game 100%.
- Zaji, one of the important characters in Shinobido: Way of the Ninja and Tales of the Ninja, appears in WotS3 as a hired ninja in one of the possible storylines of the game.
- Rokkotsu Pass, the location of the first WotS is also present in cutscenes in the original Shinobido as a resting grounds for the Kenobi Clan, one of the three ninja factions in the game. The cutscenes also include cameos from Suzu and Kurikichi, the two characters who run the restaurant during the events of WotS.
Another example of a pretty niche crossover involves the company Falcom and one of their games, Ys vs Sora No Kiseki: Alternative Saga. It dominantly features characters from the Ys series and the Legend of Heroes games, but includes tons of assist characters from many of Falcom's games. I don't even know all of them, but I would not be surprised if all of their games had some cameo in some fashion!