Love the inventiveness and the art in the event and like the egg concept.
I don’t like the energy cost. For the same energy you can get better quantity / combination of items, monsters, recruits, heroes and troops by just farming.
So really it boils down to needing to spend energy (and sacrifice efficiency in levelling your heroes) for a bit of ‘fun’ on the side. Really I’d prefer if you’re going to introduce something as a bit of fun to keep the player base amused, I’d prefer it didn’t boil down to a choice between event and your rate of progression.
I’m kinda ambivalent about whether I’ll try finish the Advanced mode for this reason. (I may have decided to push for the Sturdy shield if I didn’t already have 8 of them and no worthwhile heroes to spend 'em on)… but as thing stand (and due to the fact that I’ll likely need battle items for the latter stages which makes the rewards an absolute joke) I’ll probably end up skipping them.
And Why make the energy cost so high? It’s not like any of the rewards are super-rare (except for the Sturdy shield). Making cheaper participation (i.e. more inclusive) really will not break the in-game economy.
Anyhow… quite common for this game… give with one hand and take with the other. Can’t have our players be too fat and happy, now, can we?
To end on a positive… still love the artwork and the atmosphere and the concept.