I discovered a nice game called Cabals, which combines trading card elements with a tactical board game. But unfortunately the game was released 5 years ago in 2011. So not a lot of people are still playing, and those who do have collected cards for years. So every time I start a PvP game, first I'm waiting for a long time for an opponent, and then that opponent is far, far more powerful than I am. And the daily quests appear to only count PvP games, so if I play solo games I get no influence to buy more cards with.

In a PvP game, players are the content for other players. So when a game ages and people drift away, the content they provided is gone as well. At some point a game becomes nearly unplayable for new players, as they have nobody of their level to play with. So they leave quickly, the game doesn't get any fresh blood any more, and the dying process accelerates. Of course that hits smaller games faster and harder than bigger games. Hearthstone isn't much at risk to run out of players for some time to come. But just like the smaller MMORPGs struggled compared to World of Warcraft, other card games struggle compared to Hearthstone.

For me the lesson in this is that developers shouldn't rely too much on the presence of other players as content in their game. They need to think how well their game still would work with very few players around. Is the game still interesting enough to make players want to spend money? Is there still decent progress possible for a new player when the few other players around are all veterans?

Failing that the developers need to take measures to get new players into the game, which isn't easy. Kyy Games is hopefully pulling it off for Cabals, by getting the game greenlit on Steam. I just hope the game can be played cross-platform.