When Kramer's guys are playing Frogger on the machine that they are moving, they check the battery and calculate that they have three minutes before it dies. If they were able to power an AC-powered Frogger machine with a DC battery, they almost certainly would've known that they could've extended that time significantly by turning off nonessential components (especially the power-hungry cathode ray tube display, which is only necessary when the game is actually being played) rather than having to plug the Frogger machine in. This would reduce the machine's power and slow the drain on the battery.
The brief first exterior shot of Mario's Pizza actually shows a store front with a different name, "Five Roses Pizza". Near the end of the episode a different exterior is shown, and this time the store front is completely different and does display the correct name, "Mario's Pizza".