as another guy said before, this game, once you reach a certain point, has no need of money whatsoever: you only need the autocasted slots, then the hero experience is all that matters, your gold can go rot itself into your safe for how much you need it after that. While I like your game's mechanics, that's a pretty serious flaw you have there: other players may lose interest in this game in little time and move forward to another one. You can add upgrades to let your high-rank slots to become faster, as a quick example, or maybe, for the future, create more complex 'battles' that require you to get specific cards, for which you need to use gold ( the more different cards you have, the more they'll cost).
Hope I was of any help.
The game is pretty nice, but I think I found some serious problems:
1 - After soft-resetting the game, it appears to me that my previously unlocked achievements have no effect at all. It may be just my own impression though
2 - Sometimes, offline idling doesn't work at all. For example, I just opened the game and it was the same as I left it, 4 hours before.
Soft reset and send me a pastebin export of your code. Achievements have worked like this since game launch and we used to have people commenting about them not working but I've had it fixed for almost 4 weeks now and there hasn't been another comment since so it is likely just you.
Offline idling doesn't work if you don't have an internet connection. It is possibly that you can have a minor internet connection issue just after loading the game that could prevent offline gains from working at that moment. ~Taiga
Just a detail to report: I think I'm not the only one that noticed this, but the punk bat's animation, at a certain point, has one frame that belongs to the army bat. While this is not gamebreaking, it's visually annoying to see.
Nice game overall, I love your graphic style as well!
I really liked this game, but the levels are way too short. Also, the "less gold lost" skill is totally useless since it's damn easy to avoid being hit by enemies. The graphics instead are awesome XD I'm waiting for a Castaway 3 XD 5/5
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 "Idle Conquest"){kind=icon}
 "Kick The Critter"){kind=icon}
 "Earn to Die"){kind=icon}
 "Castaway Island TD"){kind=icon}
 "Freeway Fury"){kind=icon}
 "Portal: The Flash Version"){kind=icon}
Soft reset and send me a pastebin export of your code. Achievements have worked like this since game launch and we used to have people commenting about them not working but I've had it fixed for almost 4 weeks now and there hasn't been another comment since so it is likely just you. Offline idling doesn't work if you don't have an internet connection. It is possibly that you can have a minor internet connection issue just after loading the game that could prevent offline gains from working at that moment. ~Taiga