First of all is that they are working on the final free DLC character. For those who don't know, the game was intended to release with 22 playable characters, but had to drop two of them to get the game out on time. As a compromise, they decided to release them later on for free.
Garfield is one of the two characters. The other one is suspected to be Teenage Mutant Ninja Turtles' iconic foe, the Shredder, due to a few interesting files found when players datamined the game.They also revealed that a couple more characters - as well as stages - are being worked on. When HungryBox asked if the new characters would "grant all of our wishes" or are "gonna blast our minds", Diego simply responded "maybe," which seems to imply that two of the characters being worked on may be Jimmy Neutron and Timmy Turner. Regardless, we'll mostly likely find out who they are as development on them gets closer to completion.Crossplay is also in development, which will allow players to play against others who own the game, but on a different platform. (Thus, a PC player can play against Nintendo Switch, XBox One, XBox Series X/S, and PlayStation 4/5 users) Diego mentions that he and the team were planning on including this on launch, but felt they needed to test it out more before they included it.Finally, Diego mentioned that they are adding a "highly requested feature," which was all but outright said to be voice acting. A very common complaint amongst reviewers was that all of the characters are completely silent in the game. While a reason was never given, it's often suspected by fans that voices never happened because of budget constraints, but it seems that the game's success has finally cleared that problem.
While a date for all of these has not been said, crossplay is expected to be released sometime in Q1 of 2022.