How about a tanuki? For obvious reasons, of course.

Dogs and cats are generic, but... how about a dog and cat pair, posing together...~? Cheerful energetic dog and the more elegant but aloof cat.

This may be a bit self-indulgent, but how about adding my character, Ulrich? He's a caracal, which I think is an uncommon species in the fandom (even if the actual animal is a bit of a meme in the mainstream, unfortunately). He's a cute femboy-type character whose aesthetic is warm and cozy, favoriting sweaters and will often wear shorts, skirts, and aprons.

He really loves paws! His game mechanic, if it isn't too hard to program, could be that his cookies are paw-shaped, as I have seen paw-shaped cookies before. This shape will give the balls different physics making them get stuck in places more easily. His special ability could be something, like, "Paw Bap" where he slaps the board with his paw (illustrated by a paw print) and clears that area of balls.

His art could also be different, not the art style itself, but his penis specifically. While humanoid penises are nice, it would be nice to see a character with something more interesting. Since he's a feline, his stages could be: Clothed > Nude with Sheath > Tapered feline penis poking out > Feline penis fully out from sheath and erect > and then, of course, flustered expression with cum. Additionally, while most people I'm sure, including myself, enjoy seeing large penises, I've actually updated Ulrich recently giving him a more appropriately small feline penis. I know some people enjoy seeing the cuter small penises, so this could also be an excuse to include those interested in that (and, may, if they want a small penis but not a feline penis, an option in the gallery to switch him to a human penis, I wouldn't mind that).

This is just a suggestion, of course. Like I said, I know it might seem a bit self-indulgent, but I figured I'd offer my character since you were looking. I can show you a reference of him upon request; I don't want to be presumptuous.

So you seem like you're familair with the Japanese furry artist, Dagasi, am I right? A fan of their work, at least. Maybe you could collaborate with them in adding one or more of their characters?

Maybe you could include some kind of avian or reptile to spice things up? I don't know if they'd really work with your art style, but variety is the spice of life (especialy when every single character is a mammal).

Ps. I know this isn't what this thread is for, but I'd like it if some more of the future alternate versions of characters included more hyper stuff. It's oddly hard to find games here which have hyper content, but I don't wanna pressure you to do something you wouldn't like.

Just more hyper boyyos in general is all I ask for <3 I can't think of anything beyond that uuuhhh maybe a hung (goo?) wolf~

Are you planning on adding mod support or make it possible to add custom characters? 

Heyho!
just a question out of curiosity. Do you plan to Add Females or make a Female version of the game? 
Love the Artstyle!