These games are a bit grindy, but I guess that's part of the charm. In any case, I believe this aspect could be improved a bit. I seem to consistently finish leveling with 15–20 hearts in excess in these games, and I since you seem to have abandoned fixed drops, I was wondering how the algorithm worked. Is it exactly a 50–50% chance which drop you get? or is it skewed one way or the other depending on the enemy you're facing, etc.? In any case, I think it would be great if you could make it maybe a 55 or 60% chance to get levels, and make it so getting a streak of either levels or hearts slightly increases your chances of getting the other one (maybe 5–10% increase per successive identical drop). Also, perhaps you could drop a few minigames (like in episode 17) into each episode, to break up the gameplay a bit?
In any case, the biggest thing you could improve on is the art and animations. Really, I commend you for incessantly pumping out this story (and the English seems to have improved a bit, though it could still use some more ironing out) and coming up with new monster girl concepts; however, the uniqueness of the designs is severely undermined by the quality of the art (even if it has gotten a little better over all this time), and the animations are very basic and seem lifeless after only a few repetitions. Honestly, I don't even think you'd need to have more than the three basic scenes you currently have for each Pussymon if only the positions were more varied and the animations were better (though more content is certainly always appreciated). If this is impossible for you (no matter the reason), I truly think it would be in your best interest to seek out someone who can provide higher quality art or animations. After all, these scenes are supposed to be the main appeal of your games, aren't they? (If your vision is more akin to a visual novel, and it's the story you find most important, you might neglect the animations a bit, but you should still aim to have good art.) Maybe your patrons can even recommend someone to you.
(By the way, that "pulsating" animation when the Pussymon are standing still seems a little odd. If you want them to seem "alive" when being still, you could have them sway their heads, arms, etc., or have their chest bob up and down, but having the whole model grow and shrink looks bizarre.)