I thought it was a very enjoyable film, and I loved getting to see all those familiar British character actors getting bumped off in crazy ways. It is always good to see Dennis Price.
I wrote a review of this a while back, but it is as yet unpublished, so here is a paragraph, mostly concerning the similarities with the earlier Phibes films:
Theatre of Blood was an independent British production, very much in the style of the AIP films of the time, and it obviously owes a great debt to their earlier film Abominable Dr. Phibes (1971), reworking the idea of a serial killer, played by Vincent Price, taking revenge on those he feel has wronged him, with a running theme for all the killings. Fortunately the film is different enough that it remains enjoyably original: The killings themselves are elevated the main role here, permitting much more from Price (who as Dr Phibes is saddled with horrible injuries, and usually has to simply watch as the killings occur), while the police procedurals are almost completely written out. The tone is generally darker than that of Dr. Phibes, and certainly lacks that film's strand of straight-forward comedy, although there is plenty of dark comedy, and a very heavy layer of irony throughout.
