In WatchOS 2, there's no way to position views arbitrarily (possibly resulting in overlap) and no way to have views with custom rendering (e.g., by overriding a draw method). Why?

The API isn't quite as native as a lot of us were hoping, but there are ways around some of the limitations. For example custom drawing is possible by drawing an image and loading it into an image control, which is sufficient for a lot of situations.

Arbitrary positioning of views is another matter with the "flow" approach to layout, but you might be able to do something with a bit of creativity. For games I'd imagine it's more a case of "what can I do with these limitations" rather than "how do I do what I would like to do". The video on layout and animations would probably be a good start to see what is possible:

https://developer.apple.com/videos/wwdc/2015/?id=216

As someone who spent months on a version 1 watch app I was actually quite happy to see how version 2 apps work. I was worried that I would have to rewrite a lot of code if the layout scheme was changed, but the way Apple have designed it means that this is hopefully not the case.

I'd imagine that a future version of watchOS will allow arbitrary positioning and animation like on iOS, but maybe the hardware isn't yet up to it in terms of battery usage. Such games are clearly possible but would probably drain the battery rapidly and the last thing Apple wants with a fledgling product is talk of running out of power halfway through the day because of third-party developers writing inefficent apps. I am sure that the API will get more flexible as time goes on though, and particularly when battery worries lessen.