They were once the biggest of big box-office action heroes. Their face on a billboard was enough to sell popcorn by the tonne, and while critical credibility came and went, no one could argue their muscle in the arena of big dumb fun. But when shunted aside by a new crop of young upstarts, it is nice to know that the one-time blockbuster star has a gentle pasture to retreat to in their later years to keep the bank balance ticking over - the B-movie. Bruce Willis and Nicholas Cage both find themselves this week on the promo posters of two on-demand releases that in a normal world would have had scant hope of darkening the omniplex door. In Planet Covid, however, each of their respective outings - low-budget genre flicks designed for throwaway thrills - are on an equal billing with more lofty fare a mere swipe away.