It's disappointing to see that the devs don't seem to be doing much about the complaints. Upgrades are too pricey, coin rewards are too stingy, makes it impossible to win after level 20+, life refills take too long— all of these things make the user lose the incentive to play. I wouldn't have a "lives" feature at all, personally. You have to build your game in a way that makes the player *want* to keep playing, not limit them.