The film's biggest fault is that it opened up a month from when STAR WARS did and was totally lost in the shuffle that summer.
And nobody seemed to learn their lesson, because CLASH OF THE TITANS opened the same day as RAIDERS OF THE LOST ARK. I remember going to the first showing of RAIDERS, and walking across the multi-plex to catch the second showing of CLASH. The latter movie certainly seemed pale in comparison and I thought at the time that, if Harryhausen was going to stay around, he'd have to pick up his game.

Still, comparing TIGER and CLASH, I'm in the CLASH camp. It's only disappointing, TIGER is below disappointment.