During its Diablo III panel at BlizzCon 2009 last weekend, Blizzard took some time to talk about the game's Sandwasp enemy, which isn't very dangerous when you encounter just one but can deliver a lot of hurt in swarms.

"When you get a bunch of them together, you get what you call the 'bullet hell' effect, which is a slow moving wall of damage or death," explains lead world designer Leonard Boyarsky.

The development team initially found it difficult to envision this bullet hell concept the designers had in mind, which called for the Sandwasp to birth mini-wasps that attack players. To better get across the "old-timey arcade action" feel he was going for, lead technical artist Julian Love came up with the demonstration you see above (fast-forward to 9:04 if the video doesn't start at the appropriate segment).

Rumor has it that you can play the shoot'em up on an arcade cabinet hidden in Diablo III's secret cow level. True story.

[Via Shmups Forum]