The red line is where you fight
The classic NES system is now a playable stage!
NES is a stage in Super Smash Bros. Skirmish.
Mostly a flat stage, at times a hand reaches down and opens the cartridge slot, creating a raised platform.
None, apart from the large hand that sometimes reaches down, to put a cartridge in the cartridge slot, or to take one out.
Things to attack
You can attack the large hand that reaches down sometimes, and if you attack it enough, it will leave and not touch the cartridge slot.