The Auto-battler genre is quickly taking over the gaming community as the newest trend and I don't think I'm the only one obsessed with several of these games and the idea in general. But creating this sort of game requires either an already-existing pool of diverse characters from another game or designing a long list of units to place on your chess board.
That said, what better game to draw inspiration from than the Kingdom Rush franchise that has hundreds of units and abilities, spread among dozens of races to choose from amongst its four titles? And on top of that, the KR artstyle is clean enough not to cause clutter on a phone screen but polished enough to interesting and engaging.
You can't simply shove hundreds of characters into such a game, however, since the more possible units there are, the fewer your chances to upgrade them and create synergies between them. This is where a KR autochess could either keep it traditional and simply pick anywhere between 50 and 60 of it's units or it can innovate and bring its own flair to the genre.
Two ways to do this would be:
1. Make use of the extensive list of Heroes that KR disposes of. What if at the start of each match, you could choose a Hero unit that acts as the player's avatar, replacing the (useless) mascot that some other titles in the genre make use of. This Hero unit could have it's own affixes and force the shop to prefer showing similar units for easier synergies.
2. At the start of each match, have an option to disregard a number of affixes in order to maximise the drop for your preferred strategies. For instance, completely nullifying a few out of over 20 possible properties a unit could have leaves more space for the others to show up, making sure that you get a head start and do away with some of the RNG factor the genre comes with.
I will continue this post with a list of 60 units spread amongst 11 races and 11 classes to kickstart the discussion about the countless possibilities a well-developed universe like Kingdom Rush offers to the auto-battler genre.