Is there any way to increase the speed of gameplay in Plants vs. Zombies? It's a great game, but it can get a bit slow.
The game offers no such option.
Try Game Speed Adjuster.
There is one mini game that speeds the game up. It is called "Zombie Nimble Zombie Quick" but this is only for one level and there is no way to slow it down when needed, so you may get overwhelmed very easily. Otherwise, the answer is no.