Just tried the full version and it's just a blast, a very fun score attack game akin to early 2010's mobile games, and I'm super satisfied with that purchase! I do see that there are some plans to update it, and I see that the tornado is going to be adjusted, which was really my only issue with it so far, however since updates are on the table, I figured I'd drop some ideas and features I'd absolutely love to see:
1. Make the Shark Woman (or enemy) Burp after eating you - She has a really great design and I like her quite a lot, to be honest with you most of the changes I would love to see are based around her. Though I noticed there is a great burp sound in the game already after getting those pink pearls, I thought it would be great to have her burp after eating you, even using that same sound if you wish as it is a good pick.
2. Playable Shark Woman - Looking at how her animations work and how her belly grows smaller after she eats you, I think she would be a great playable character as well. There are a few ideas that could be cool with this, such as her being an unlockable, or just unlocked off the start. If she were to be playable though, you could have the Mermaid as the threat instead, as a sort of role reversal, giving her the same treatment (Why I said "Or Enemy" on #1). I think below you mention other game modes being a possibility, this could be one if you wanted, I think it would be awesome to see her playable as well.
3. Unlockable or Available Cosmetics - one thing that this game would benefit greatly from is a choice of skins and possibly backgrounds, as a lot of earlier mobile games flourished because of these. I think having a few different skins in the game to choose from would spice things up a bit, and keep players striving for new high scores, as they would earn new skins based on the higher score they got. This could range from character skins and recolors, to even new Mermaids or even the Shark Woman as previously mentioned (Since this game is NSFW marked, the highest score should give like a nude skin or something, I think that could really get people wanting to play more), to music choices as I did hear multiple tracks in there, and maybe even new stage backgrounds, as I think that could look cool. These changes don't have to be too crazy, but I still think having a handful of these could do well for the game.
Overall none of these changes would be required to make this game great, as I think it's an extremely polished and clean experience that I'll definitely be enjoying for a long while, and I just wanted to say thank you for that. It would be really cool to see these changes, but they are absolutely not required, and are just there to maybe give some inspiration as to what I think could be cool to see. Thanks again for making this!