found a heavy game for my LG Optimus 2x (dungeon defenders), playing it smoothly but soon after i had low battery, so i set it to charge while i was playing, a few hours later i stopped playing and looked how much the phone had charged... nothing (maybe discharged some).
as for playing Full-HD movie, it didn't take my Full-HD mkv so well, nor did it take only HD avi files well. so if you wonna play movies on it, you might wonna convert it to something the phone is good at playing like 3gp files like the phone is recording its Full-HD, but when you are already converting, you might aswell cut the video to the phones size.