Play-goers, beware. Director Robert Icke is back in town, and that means a turgid four-hour revival of a heavyweight classic with every actor screaming, bawling, weeping, howling and generally overdoing it. But here’s a surprise. Player Kings, Icke’s new version of Henry IV, Parts 1 and 2, is a dazzling piece of entertainment and the only exaggerated performance comes from Sir Ian McKellen who plays Falstaff, quite rightly, as a noisy, swaggering dissembler.