Yes, the game is still being updated. There are no command inputs as of now, though (if you mean stuff like 236X, 214X, etc.). Closet thing I can think of are combo routes (Examples: L-L-L-H-M x 8 for Mario).
To parry, you have to walk, then stop moving right before the attack hits. And yes, there are more of those moves too (Like M>H in the air as Luigi , or L>L>M as Mario)
