it is just imho, but I think you should not play them for awhile if you don't have enough time for them. I always put my tamas away for some weeks/months once I find myself having no time for them because of studies or anything else, for I usually feel guilty for not being able to care for them enough. just feeding them snacks is not really a way out, and leads to an unhappy tama (and an unhappy owner...)
ps.: please do not feel offended, I did not mean to sound offensive, that's why I stated it is only my opinion. we may operate differently