We want our employees to work - but we want them to work productively. One way of doing this is to create parameters within which play (of some kind) is allowable - perhaps at lunchtime, perhaps on Friday afternoons, perhaps for 5 minutes every hour.
What 'play' can do is allow staff to recover and re-energise ... or deal with small domestic issues (like booking a plumber) that might be distracting them from their work. If you don't give them 'playtime' they'll probably take it anyway - by working more slowly and less effectively.
So, take control of that playtime - build it in safely into daily or weekly routines ... and then you both reap the benefits.