You might also want to try Cyber Core. It's a lesser-known bug-themed shooter. Some say it's average at best, but I think it's fun. Cheap, too. Got mine for $10 (on ebay). Actually, sometimes you can come across veritable treasure troves of PCE/Turbo stuff being sold on ebay, and for cheap, too, so I'd reccomend keeping an eye out for good deals. Most US-released HuCard games will be no more than $20, usually less (except for Magical Chase, Soldier Blade, etc.).
Some other places to look for Turbo stuff:
McVan's Games
Diskounter's
Imports:
Game Choice Club
Mad Gear Games
Wolfgames
