The downloadable version has the same content as the web version, but you can download it here: https://fancyfishgames.itch.io/aground if you want to play the game offline.
When we launched the early access version a little over a year ago, we stopped adding free content/bosses (we still add updates with bugfixes and new features though). There's a lot of new stuff in the Kartridge full version if you want to take a look!
 "Idle Monster Frontier"){kind=icon}
 "Dinogen Arena"){kind=icon}
 "Chaos Faction 2"){kind=icon}
 "Aground"){kind=icon}
 "Kingdom Rush Frontiers"){kind=icon}
 "Strike Force Heroes 2"){kind=icon}
 "Outpost:Haven"){kind=icon}
 "Vault of Xenos"){kind=icon}
 "Strike Force Heroes"){kind=icon}
The downloadable version has the same content as the web version, but you can download it here: https://fancyfishgames.itch.io/aground if you want to play the game offline.