You technically have the choice of Just Dance 2018 as well, but you probably shouldn't be picking that over Arms or Mario Kart.
The deal is available today only at JB Hi-Fi, which is running their Wicked Wednesday deals again. There's discounts on a whole bunch of things, but from a gaming perspective one of the better deals is the Switch bundle for $488 with Mario Kart or Arms.
There's also a decent offer on a Xbox One S with Forza Horizon 3 and NBA 2K17 for $299, which is a cracking price for those who want a 4K Blu-Ray player but wouldn't mind something to play games on as well.
Either way, you only have until the end of the evening to take advantage of the offer. JB stores will be open until 9:00PM tonight AEST, except for the megastore locations at Piccadilly, Mandurah and Homebush. (The $999 offer for a 64GB Samsung Galaxy S8 isn't bad either, if you like buying your phones outright.)