GamesBeat: The number of squares in the game is interesting to me. It seems like coming up with the perfect number might not be so easy. You have to put some thought about how many squares to have on each side.
Yee: Mohan Belani is our lead designer. He has an advanced math degree, so he’s about as smart as five Bernies put together. [Laughs] He thinks about this stuff all the time. He’s clearly thought about the combinatorics of board size. We’re also restricted at some level because it can never be too many squares. You want it to be visible and playable on an iPhone.
GamesBeat: What about some of these very expensive plants, as opposed to the inexpensive ones? You can think short-term or long-term in your strategy.
Yee: I was just in a meeting about this with the designers a few days ago. The relative pricing reflects what we think they’re worth. If it’s a better plant for you, we’ve priced it higher. That’s what we were thinking. That’s why sun and seed slots are slightly higher, because the benefit of those upgrades is really significant.
Above: Plants vs. Zombies 2: Pirate Seas map.
GamesBeat: I thought the cannon was a lot of fun, but it was kind of a luxury. I quite often went for the triple peashooter instead of the cannon.
Yee: I feel that same way too. I often get the cannon because I see, in the preview map, that the imp cannon is on the other side. It’s a luxury. It’s expensive. But if you’re getting overrun by stuff, it’s very valuable. I don’t know if it’s rational, but for some reason, like I say, I tend to use it when I see the imp cannon on the other side. I don’t know if that makes sense or not.
GamesBeat: Can you explain how you came up with some of the new types of zombies? Were there any that didn’t make it into the game.
Yee: A few didn’t make it in, but we can’t talk about it, because they may in fact be re-animated for another world. The zombie I love is one of the first ones you face – Ra, the sun-stealing zombie. A lot of Plants Vs. Zombies one players will say, “What the heck? That dude just stole my sun!” It’s a fantastic moment. I wanted it to be harder, actually, but then the designers yelled at me. “Let’s make it harder! Let’s make him not give up the sun after he gets it! Let’s make him steal the sun faster!” The designers said we couldn’t make the game so hard. It’s a great example thematically, though, since Ra is the sun god in ancient Egypt. I love how that came together.
I really hate the parrot. I’m loss-averse. That’s my cognitive bias, to be loss-averse. I hate it when I plant something like the threepeater and the parrot comes and takes it. I spent this sun. Why are you stealing this from me? The parrot’s small. You can’t see it right away. It drives me crazy.
GamesBeat: Yeah, the parrot got me a lot of times. I figured out you had to hit that captain guy to take him out.
Yee: Yep. You have to take him out quickly, before the parrot jumps. That’s tough. I think stealing sun faster is better than the parrot, but the parrot does change gameplay a lot. It forces you to track a new thing.
GamesBeat: I appreciated the familiar plants as well, like the butter-lobbing corn plant.
Yee: It’s funny, because one of my favorite bugs I ever posted was, “Butter state on zombie not effective,” or something like that. We were going through bug triage and one of the bugs was, “No butter state for piano playing plant.” I posted it to my Facebook wall as the best bug I’d ever seen.
GamesBeat: What are some other things people are pointing to as the funniest additions?
Yee: Everyone loves the farting bean. When the zombie eats a bean it farts and dies. Everyone loves that. I love the yeti, because I like to optimize my coins. Whenever the yeti notification appears, I jump and I play the yeti level. I love the fact that the yeti is actually—Well, I shouldn’t spoil what the yeti is.
I love the bonk choy myself for tactical reasons, but people all seem to love the bonk choy. I don’t know what it is – the character design, the artist who did the work, the fact that it’s a little melee guy and he punches people. He does that uppercut knockout blow. People love that animation. That’s an example of what I think makes a Popcap game. They did that one series of animations just for the death. That’s the kind of stuff that Popcap does, and a lot of studios wouldn’t.
Above: Plants vs Zombies 2
GamesBeat: I like the butter landing on the zombie’s face. That’s always cute.
Yee: I’ve never understood that. I’ve actually talked to the designers about it. Why does the butter stun the zombies? Because its face is covered with butter and it doesn’t know what to do?
GamesBeat: When you design these things, do you design them as a plant and a zombie together in a sort of rock-paper-scissors arrangement, where one counters the other?
Yee: Sometimes the world team will give a designer an idea. Sometimes it is that rock-paper-scissors type of thing. We were just talking about how, when we hire a new designer, we should bring them on board with how we create the zombies. The designers said, no, there’s really no one approach. They’ve come up with zombie and plant combinations. Sometimes they just have one idea, though – an area effect or a melee fighter or something with an Egypt theme that eats sun. They do it in all kinds of ways. There’s no one simple way.
I can say, though, that any one zombie or plant has to work with so many others. The balance considerations are gigantic. That’s one of the reasons why it’s fantastic having an advanced math guy to think about a lot of this from the beginning. A designer with more of a story background may not immediately appreciate the mathematical intricacies.