I really like the variety of enemies in this version. Most of the other versions (or at least the first 3 I haven't played the Milky and Honey one yet) had a lot of the same enemy types of the bosses, the three kinds of one-directional-movers, but this one also has the rainclouds, the crabs, and the sun, which help spice up the levels, despite the minor differences. It is missing any sort of chasing enemy like the Choco-Bunnies in the Easter edition, which probably makes it a bit easier, since the equivalent Sun enemy is generally more predictable and easier to deal with, and is often placed somewhat out of the way in the map, as opposed to the Choco-Bunnies, which were usually put in very key locations, but I digress. Another thing I noticed is that the Flower Rider Bun boss projectiles had gravity, unlike the equivalent ones in the other games. I feel like this makes it a lot more balanced in terms of difficulty with the Basket Copter Bun, although maybe still a bit harder given the trail that both it and its summoned buns have.
Which brings me on to my one main criticism, if you can even call it that. When I went into the settings to adjust the audio, I noticed the difficulty selection. I was going to check if it had a hard mode, but the only alternate difficulty option was Chill (presumably an easy mode). When I started the game, I didn't know whether I would've wanted to play on a hard mode, but upon reflection, I think that if there was a hard mode, it would have been more fun. If possible, I would love to see a hard mode in later installment(s) in the Wanna Peek? series.
And yes, I recognize that I may be in the minority here in wanting my lewd games to have a hard mode in them. But, I feel like a hard mode, for those who are return players to the series or just those experienced with this style of game in general, would improve the experience a lot, and even improve replay value for newcomers and veterans alike. In this version, I completed the game without losing a level once, whereas a lot of levels took me a couple tries in the Easter and Christmas versions. This might just be because I learned to play better, but I think that the easier difficulty in this game's stages played a part as well. So yeah.
Another suggestion that I don't really expect you to add in later games at all (but I'm just putting out here just in case you feel inspired and do end up wanting to add it) would be some sort of Bonus or Endless mode, maybe that unlocks after you've completed the game. I imagine it would be essentially a score contest of trying to get the most level clears or points without losing all your lives, with random characters in the backgrounds. Maybe the further you got in, the less time you'd get per level, or the less powerups would drop or more enemies, or something. You might even get unique gallery pics if you got to certain milestones. I personally would enjoy that, although IDK about anyone else, so I don't know if it'd be worth the effort to program in. Maybe once you've got some more games in the series, you could make a single game that combines all the other games into one game and add the endless mode into that?
TL;DR - I liked this game a lot, as per usual with your games. I especially liked the variety in the levels in this one compared to the others I've played, although I did find it easier than most. I think it'd be cool to have a hard mode in future installments for those who are veterans of the Wanna Peek? game series, since there are getting to be a good number of them. I also think some form of endless mode with a ramping difficulty would be cool as well, but by no means necessary.