Paintball is definitely played in Vietnam now. There has been a recent boom with at least 5 fields in operation in Ho Chi Minh City alone. You have:
Sung Son Tri Long - District 12
Cong Hoa (airport area) - Saigon Paintball
District 7 Paintball
District 9 Paintball
Tri Long has a speedball field and can do 4500 psi fills (the only field that supports tournament style play and only supports HPA, no more co2). The rest are recball only. We are setting up the first pro shop, you can check it out at facebook.com/VietnamPaintballCafe. Recently, Tri Long even took a team over to Malaysia for the MPOC 2nd leg in Kuala Lumpur. Things are on the way up!!