Splinter Cell was always developed with the original Xbox in mind, and every other version was ported from there, so it doesn't surprise me we never saw a portable version of those older titles, since Microsoft never did a handheld.

Speaking of, every incarnation of that original Splinter Cell game is just a bit different, depending on the system you're playing it on. I need to do a dive into that stuff at some point too!

Metal Gear, of course, has its portable games like Ac!d and Portable Ops, but naturally they are nothing like the console incarnations.