Nyoronoru has compiled another excellent guide for Tatsunoko vs. Capcom, this time for the giant character PTX-40A.Since PTX-40A is a giant, he has no partner. To make up for this deficiency, PTX has extremely powerful Super Armor made to blow through any attacks that strike him. PTX can still block without having to rely on his super armor, and he can Mega Crash, Advance Guard and Baroque just like all the other characters.
PTX has a very nice special moveset, but since his Level 1 Hypers are really useless even if they land, it's hard to play a good game with him. Your entire goal should be to build up meter and land L-P (your Level 3 Hyper) as quickly as you can. Also try to land a Snapback if at all possible, it is vital to knock off the red life that opponents gain. Baroque all dangerous situations and once your opponent gets to 3 Hyper levels, play more defensively.
Also, if the concepts in this guide are going over your head a bit, make sure you read the basic gameplay section for Tatsunoko vs. Capcom, as it explains a lot of the techniques and terminology you'll want to know about.