Playing a Real-as-Heck video game today, so don't mind me~ 
Uncovering some of the Deep Lore about Bug Panic, it appears to have its roots in Cave's feature-phone output, a game called Mushihimesama Gaiden (虫姫さま外伝) which plays very differently but seems to be where Reco's sprites in Bug Panic come from.
The link used to be more direct too- an early time-attack version of the iPhone game, shown at 2009 Cave Matsuri, was called Mushihimesama Gaiden: Bug Panic. The 'Gaiden' was dropped when the game was properly released.
Oh, and if the music in the feature-phone Gaiden sounds familiar, you are someone of excellent taste- the main theme was remixed for the Mushihimesama OST under the title Princess Reco's Adventure
OK, one last thing about telephone CAVE games- a release article for Mushihimesama Gaiden from back in 2004. It was distributed via a mobile game site, Ge-Sen Yokucho
(Finding info on these games, as I'm sure you can understand, is a real headache!)
dengekionline.com/data/news/2005…
(Finding info on these games, as I'm sure you can understand, is a real headache!)
dengekionline.com/data/news/2005…
