itch.io

You can play with as many players as you like! The waves of opponents come on their own and can be managed by a GM, neutral player, or just anyone else. Each round starts with the players taking their turns - each player can do something during their turn as outlines in the rules. If I’m playing this within a larger game, I like to let the players use their existing character’s skill in some way - casting spells, using items, etc.

The more players you have, the easier it is to defend the tower, so it might help to increase the number or strength of opponents if you have a lot of players. With the rules as written, I find it works well with 2-4 players.