HOPA stands for "Hidden Object Puzzle Adventure". These games are basically puzzle games revolving around a story. I recently voiced the game Dangerous Games: Illusionist Collector's Edition, available through Big Fish Games. 

"The first annual Championship of Illusionists ended in tragedy. Twenty years later, the event is back, and you've been asked to write a story about it. It promises to be entertaining news... but things go straight to the front page when a mysterious red-masked man appears out of thin air to abduct the first contestant! Stranger still, the hotel owner claims the man died during the previous competition! Who is the mysterious Red Mask, and what does he want? You'll have to unravel a series of strange and mysterious illusions to find out. Just be careful – nothing is as it seems in this exciting Hidden Object Puzzle Adventure game!"

This is a special Collector's Edition release full of exclusive extras you won't find in the standard version. As a bonus, Collector's Edition purchases count toward three stamps on your Monthly Game Club Punch Card!

The Collector's Edition includes:
Challenge a familiar enemy in the bonus game!
Collect tricks of the trade
Earn achievements
Enjoy concept art, music, mini-games, and more!
A comprehensive Strategy Guide

Go to Big Fish Games for more details