One planet coin per level, rather than every fifth level, or five planet coins every fifth level. Add a 20-pack of planet coins somewhere in the daily rewards. Don't be so stingy because people will still spend on your game!
@ Meep - This may be a game "run by evil ownership" to you; however, the owners are running a business here, so it only makes sense to reward people that donate. This wallet warriors insure that the game remains free to play. Otherwise, how could they afford to run the site? If you put things into perspective, IGG cannot please each individual in the game and at the same time keep a genuine balance.
Food for thought.
Best,
Tim