Super Mario Maker is a beautifully crafted and unique game and it feels like Nintendo have put honest time and love into creating it. Other than the fact that timing a jump on the springboards is still horrifically challenging (but it has been for as long as I've been playing Super Mario), you simply cannot fault the meticulous production quality. The simplistic charm and fabulously colourful world will keep you coming back for more, but for how long is really dependent on the player and the reasons they love Super Mario in the first place.
One of the first rules of game design, or design in general, is to establish function before working on the form of the piece. There is simply no point in having a game that is stunning to look at and listen to, when it just isn't fun to play.
Heroes of the Storm isn't a perfect game - but it's not far off. The faults are minor and largely overshadowed by the many positive aspects. There really is very little risk in giving this game a go - it's free, the games are short and you don't have to take it completely seriously - and the payoff is well worth it, and more.