I always find people calling things shovelware tiresome as that word does have a specific and very useful definition, but most people use it just to mean "Any game I do not have interest in that has a budget smaller then a AAA title." It's especially depressing when a game being made by an indie studio that is clearly putting in a lot of effort and passion is given the reception one would expect from a poorly-optimized iOS port.
Something something Avatar being the Fire Emblem of NASB.
I think I have seen basically every franchise with more then 2 fighters be compared to Fire Emblem by someone at this point - SpongeBob, Teenage Mutant Ninja Turtles, The Loud House, and Avatar... I haven't seen anyone give the label to Ren and Stimpy yet, but I bet someone will bust out the FE comparison if Ren and Stimpy end up being separate and therefore the game gets three slots.
It is kind of funny, as I don't think any of them really work as comparisons. SpongeBob is one of the most famous children's shows in the world, Teenage Mutant Ninja Turtles is the biggest IP in the game if we're sorting based on what IP has pulled in the most money, The Loud House is the biggest modern show (and, by extension, the biggest modern show that people generally expect to be good, as modern SpongeBob can be, er, an experience), and Avatar is literally considered one of the best TV shows of all time.
These are all... pretty big IPs worthy of content in the game, but I guess Nicktoons will always be biased by age groups more then video games are, so people are more likely to just dislike the modern picks. I've seen a lot of "Every Ninja-Turtle/Loud-Sibling/Bender will play the same" hot takes, which... doesn't exactly exhibit deep knowledge of the IPs.