I've been playing this game for a few months now and I've noticed that it is constantly running events weekly for new monsters. However I have found several issues with the game itself that need to be dealt with instead of these constant addition of monsters.
For one, creating monster eggs from the lab, once you collect it, it states it can be found in the storage yet you can only place it in the hatchery then and there or else your slot remains filled without the option to use another without spending gems.
The obvious solution is to let you place these eggs in storage, allowing you to start creating a new egg whilst the hatchery opens a space over time.
Another idea is that as long as your free egg creation is no longer working, you can use another container without the need to pay.
Personally, I'd prefer making a permanent unlock for each extra container like 100, 200 and 300 gems but seems unlikely.
Still, moving eggs to storage is something so obvious and yet still missing.
Another issue I've come across multiple time is Corrupted leaves can only open one chest at a time and it is so infuriating, spamming the buttons over and over again. I personally collect roughly 150-200 leaves but I'm sure there are those who collect more and it's just a huge waste of time instead of just letting you open all at once.
A more recent issue I've noticed was the Breeding Boost you pay for temporarily. I was already aware that if, for example, you were to breed what would normally take 5 hours but with an 80% boost, drops that down to 1 hour. If the boost was to end say, 30 minutes in, the time then readjusts to 4 hours and 30 minutes which just completely wastes the time for your boost. This also applies to completed breedings as breeding is so much faster than hatching with an 80% boost that the hatchery is so easily filled with completed breedings that you can't collect as you also can't collect to your storage which would be very helpful.
What I suggest, a part from collecting eggs to storage is that if the boost was to end, the time should adjust based on the bar. For example, following the same example as about, if 30 minutes of that 1 hour was to pass before the end of the boost, the time would adjust to 2 hours and 30 minutes, thus taking advantage of all your boost time. At the same time, a completed breeding should not just jump up in time from complete to incomplete just because the boost ended.
I had a 1 day 22 hour Legendary breeding, dropped down to 6 hours 35 minutes, a huge time saver. I boosted with ads to get it completed before my boost ended, without space to place it but figuring it was complete so that's it, only to come back on and find 1 day and 15 hours left til it's ready to collect.
I may have forgotten some issues so if anyone has any other ideas, please post below but these are some issues that need to be resolved instead of constantly adding more monsters.