there are several major flaws in how this is a free game. first of all its not because you cant fully enjoy the game without paying. the main cause of this is elevator costs and energy uses/capacity
these are my suggestions:
1. elevators should be reduced to 5 ME
2. you should be able to pay elevator fees with crowns as well; i.e. 20-50 crowns
3. revival shouldnt double cost evry time
4. ther should be a system that if you dont play for 48 hours energy gained after 100 should be 50 per 24 hours
5. max ME should be raised if not alot at least 200
6. there should be special benefits to energy buyers that, eventually are accessible by free players
if you have any more suggestions for enrgy economy improvments or problems with alredy posted please post them
6 is already the case. Energy buyers can access things like 3* equipment faster than free players. Energy buyers may get occasional bonuses for purchases (like the rose regalia), but those items are often then sold between players so a free player can potentially get one.
1, 2, 3, 4, and 5 are not good ideas. The game already gives plenty of mist for free. One can play for more than an hour a day on mist energy alone and then crowns can be used to purchase more energy for more playtime or crafting. Reducing the CE needs as you suggest would remove a significant motivation for players to pay for CE. It's good when players decide to pay, because money is needed to pay the developers and GMs and to maintain the servers.
It's nice that players can play for free, but those free players already get more than they pay for and need to be encouraged to pay by having their play limited as it is. I think the mist amount given to free players is spot on.