I've been sitting in the Enterprise space as a UX mercenary for probably around 5+ years. In every team, sales meeting and brainstorming session I've always encountered resistance around "maturity" in terms of design. The more money that is being spent on the software, the more "serious" the design should be. This line of thinking I think typically comes from the concern that if the design is not serious therefore the trust around it's ability to do the various task(s) will be eroded. The thing is, the more sales meetings I've been in or participated in the preparation for the more I've come to the conclusion that "design" isn't even a bullet point in the overall sales pipeline. Sure the design makes an appearance at the brochure / demo level but overall nobody really sits down and discusses how the software should look or feel during the process. Furthermore the client(s) typically have invited the sales team(s) into the selection panel(s) based off their existing brand, known or rumoured capabilities and/or because they are legally required to. To my way of thinking, being "playful" with your design is a very unnerving discussion to have in such a scenario. The moment you say the word "playful" most people respond with some word association positive or negative (usually negative) as the word may take you back to your childhood (playing with lego or dolls ...I didn't play with dolls..they were called G.I. JOE'S!). It's that hint of immaturity with the word that makes it more appealing to me, as it forces you to think about maturity but with the constraints of immaturity (cognitive dissonance). Playful however doesn't have to be immature, there are very subtle ways to invoke the feeling of making something playful without actually being obvious about it. For example, Google+ and most of Google's new branding is what I'd consider "playful" but at the same time the product(s) or body of work that goes into their solutions are quite serious.Why be playful? My working theory is that the reason why users find software "unusable" has to do with confidence and incentive. If these two entities don't' fuel their usage furnace the overall behaviour around their usage decay(s), that is they begin to taper off and reduce it to an absolute "use at minimum" behavioural pattern. This theory is what I would class as being at the heart of invoking "emotion" or "feeling" into how software is made and often why a lot of UX Practitioners will preach as to why these two should be taken quite serious in the design process. The art of being playful in a way regresses adults back to their childhood where they were encouraged to draw, build and decorate inanimate object(s) without consequences attached. As a early teenage child, you were encouraged to fail, you were given a blank piece of paper and asked to express your ideas without being reprimanded. You in short, "designed" without the fear of getting it wrong or for that matter right (although right was usually rewarded with your art piece being put on the fridge at home or something along those lines). A playful design composition can be both serious but inviting, as a good design will make you feel as if you're "home" again. A great design will make that temporary break away into using other software and then back again an obvious confidence switch - as if you're saying out loud "gah! that was a horrible experience, but I'm'm back to this app...man...it feels good to be home and why can't other software be like this"