Copied from the moderator at PiracyGames subReddit NotIsaacClarke:
Ads built into the game at runtime: https://i.redd.it/x1gz0rbix1721.jpg
DRM added to their releases which prevents the game from launching if removed: https://i.imgur.com/pNjo10d.png
Cryptominers and startup malware included in their games: https://www.reddit.com/r/Piracy/comments/bzczk6/i_think_i_found_an_infected_game_on_igggamescom/eqsqqj0/
Attempting to install browser hijackers: https://www.reddit.com/r/Piracy/comments/apcvx4/here_we_go_again_igg_this_time_im_not_reporting/
Javascript malware on their website: https://removeddit.com/r/Piracy/comments/9f1rf2/igg_games_now_downloads_adware_into_your_computer/
I like to go by the saying "Fool me once, shame on you, fool me twice, shame on me".