By one hand the progression of feed cost is too high: 1500 satoshi is incremented per  upgrade. So to purchase 20 upgrades (and get a daily total amount of 35 feed to use), it would cost 315000 satoshi, in total expenses. To get 45 upgrades, 1,552,500 satoshi (0.0155 Bitcoin)
I agree that maybe that initial promo was too "generous"...

Yet to use the 60 feed it would get us stuck to game 5 hours non-stop, if we are able to feed 12 times per hour (taking in count the completion of captcha, it is not possible, at least manually). So I don't agree that it is for basically 'nothing', actually it requires to complete captchas. To complete a captcha every 5 minutes during 5 hours it may be really boring, and even tiring if you multitask with other games/faucets.

 Even if we feed 10 times per hour, that would mean 6 hours playing the game non-stop. So regarding those players who were able to increase the total feed amount to 90-100+,  I can only think that bots were/are involved, if they can use the full amount of 100 feed daily. So I guess you may wish to check how to stop any bots activity.

So, let's consider I can use, daily, 30 feed in 3 hours of time. The bear would require 5 days to be fully fed, at current settings. That is a profit of 24,000 satoshi/day. At such rate it is possible to earn much more at current Robot Coin Game with less efforts (less captchas involved, and taking in count promo and social networks). Maybe +50% earned daily, depending the Zone.

If I consider other games (I wont say the name of that game here), there is a game which may allow to earn 80,000-100,000 satoshi daily at top level (depending how often the game can be attended). That game is just advertising based, and it can not be invested in it, just use earnings to progress in game.

So that is why, following my "rant" in a previous post, the Wonderland critters game loses some attention and position in the top rank of games I play. It was fantastic before nerf (though it took quite an effort to spend 40-50 feed daily), but now, I am not sure if it is still worth the time. I will keep using for some time and decide.