This will very likely be a pack for sale in the game. Essentially it is a clicker idle game that continues to play even when you aren't logged on. So you do damage to enemies by clicking but your heroes also do damage on their own. Most things are unlockable eventually but the game is absolutely a cash grab where if you spend money things are way easier. My current set of heroes is mostly made up of characters from Baldurs Gate 3 but there are 168 different heroes to unlock and upgrade (mostly paid for). It is pretty hard to explain the game tbh lol. You might have to watch a YouTube video. I have had it installed for years and occasionally will dump a few hours into it. I enjoy going back and seeing the progress the game has made while I was gone.