I've played this fairly amazing vore game for a good while now, and im ready to give it a proper review. In a nutshell, it's super replayable, simple to control, and moderately challenging (save for a couple grievances).
As a "size" person, i love how enormous you can become, as well as how huge bellies get as you gorge schools of fish - only to use your prey to grow and therefore enable even more *unhinged gluttony.*
I have a few criticisms, which are the following;
The mines and toxic sludge should affect both the player and sharks that pass through and otherwise come in contact with each. While you can detonate mines yourself in attempt to catch sharks in the blast to shrink them, this risk is not rewarding at all and even hurts you much more in the long run due to sharks leaving after 3-4 dashes, causing to be at a significant disadvantage for the rest of the run as you try to catch up and get the size you lost back. Striking multiple mines means you wont be able to further contest the increasing shark sizes during that run - pred mode allows absolutely *no* mistakes regarding that as well.
Toxic sludge not only slows you down, but harshly drains your size whilst inside. Being able to bait a shark into it would be really nice to make marathon runs and the mermaid requiring 100 sharks to be nommed more bearable.
Despite being intended for player defense, Bouncy Corals have no notable movement-stopping effect on sharks unless they hit around 2-3. Additionally, the player trying to hit one head-on to defend themselves is generally a bad idea, as the player (unlike the shark) will come to a complete stop for about half a second due to significant difference in acceleration - plenty enough time to get charged down and gulped as you already took the coral down one durability.
Instead, make coral's slowing effect affect only sharks, and increase the collision force that players can exert on it by bumping into it so they can knock it right into an incoming shark warning sign to buy them enough time to get out of the way.
Given your likely large size at the time they begin spawning, the squid powerup is just... not good. There's nowhere to really dodge to given the previous two hazards that begin spawning before the squids do, and trying to do so usually means you will bonk a coral or mine, and get knocked right back into the waiting mouth of a shark you tried to escape.
I propose it work like brief invincibility instead - the player gaining 2 "afterimages" as she swims, which one afterimage will disappear upon a shark attack (causing the shark to swim right past you), or causing the detonation of a mine blast not affecting you.
Using the eel dash and squid decoys on mobile is a pain with just how quickly you need to double-tap. A small, translucent button near the right (or left, for lefties) would solve that problem.
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As for suggestions, mermaids having unique powers should be altered into an upgrade system to continue giving goldfish a purpose - each upgrade possibility being the already instated dive speed, cheek capacity cap (Fucking love enormous cheeks), power up duration, and a new trait being maximum multiplier/belly size, and slower digestion speed.
im not sure how it works entirely, but I really feel that the growth/rate from fish needs buffed altogether.
Crates' likelihood of spawning is pitifully rare, and considering that a heart fish's size increase potency is no stronger than a heart egg's, I really think that the heart fish's size it gives should be substantially increased in value to make it's rarity justified.
There are seemingly three currently, so two larger, rarer size tiers for the existing schools of normal fish for the purpose of helping the player both build and keep their multiplier.
Sharks and mermaids getting a few new color palettes to play with would be my utmost wish however, or even being able to make a custom mermaid via color presets affecting the hair, skin, tail, pupils, eyeshadow, and lipstick as a reward for 100%ing the game.
This is a good game on the verge of being a great one. All it needs in more time in the oven. I understand that game dev is hard, so i understand if you still decide to leave the game as is.