Unessential.
And I would like to say that developers should do handheld games some justice. Just because it's smaller compared to it's console counterpart doesn't mean the fun should be diminished too. Not that I'm mad.
OK back to review.
Game is decent stealthy fun. It's what you expect on a SC game. Missions are challenging but it goes a little bit hard especially when taking down enemies up front..
Controls takes a short while to getting used to. The camera takes a little bit of practice and tolerance but can be detrimental at times. NOTE: mapping camera controls in the same buttons(or analog stick in this case) as the movement control is not a bad idea. It's worse.
Splinter Cell Essentials offers some decent fun if you crave stealth games on the PSP but it's faced with minor issues and it's low on content that you're better off getting the PS2 games for a Splinter Cell history lesson.
Double Agent best evah.