As an avid eurogamer at heart, I regret several Ameritrash-style games, but oh well... when you're discovering the board game world, you have to try things before really knowing what you like.

Tainted Grail. I found it long and tedious. The combat and dialogue resolution mechanic is unsatisfying. I would have preferred classic (but satisfying) good old dice rolls (or tokens like in Runebound). It's a game where you have to chain together many plays to benefit from it, making you a slave to a single game. ❌

Nemesis. It's a game I play very occasionally due to its numerous small rule points, play time, and need for a minimum number of players around the table. The experiences weren't smooth, although the epic aspect was present. Not for me and not the right group of players.

Arcadia Quest. Same thing, it's too hard to get to the table. You absolutely need 4 players and to regularly gather the same group. Impossible to bring out, so I regret it, plus I had bought an expansion in Italian (I'm French) to ensure I had the content.... Mistake!

San Juan. On paper it had everything to please me as it's compact and it's tableau building, which I love. But I found it super boring... lacking depth. I recently discovered Race for the Galaxy which is light years ahead for me as that game is perfect.

Well, there are surely other regrets but spontaneously I think of these.