So, first suggestion is: give objects an option that allows them to pass their triggered state to compatible adjacent objects. This could be done by adding another object property, "pass to", after "group" & "collide with".

So if there are 5 cubes standing flush to each other, each from group 1, each with "pass to 1", touching just one of these cubes would trigger the rest. This alone would have cool applications, but it would work even better if we got more than 4 trigger groups.

Second suggestion is adding a "logic gate" object property that would allow us to make logic gates. Suppose you make a dance pad of 25 cubic tiles, each from group 1. Right underneath those tiles you have one big tile from group 2 that will only be triggered once all the objects from group 1 are triggered. An AND gate.

Objects could have "Logic gate" menu with options like "All from", "Any from" and "Neither from". It could also include a separate group option to specify which group it's referring to, or if that's too cumbersome then it could just refer to whatever "collide with" group is set to.

Obviously this isn't the most important feature to implement for a fighting game (there are many I'd rather see instead), but it would be cool if it was added at some point down the line. Could make some neat mods with it.