So I started on a new game to pass the time - currently called just 'Snowman' it currently looks something like this:
Not very exciting to look at really - I've deliberately ignored all of the graphics side of things, so at the moment it's basically just drawing the collision bounds for everything. The black and yellow lines show the level surface (yellow being the currently active surface). The circle is the snowball you control, the crosses are items to pick up, and the green box is a signpost/switch to decide what path you'll take next.
The final game will have two halves - the 'level' bit (shown above) is what I'm currently working on, where you roll your snowball and pick up decorations. The 'village' bit is where you can build snowmen from the snowballs and decorations you've collected from the level bit (which I havn't started yet).
I'm reasonably happy with how the levels play at the moment. They're not quite as fun as I'd like, but I want the focus to be more on the snowman building / village side rather than the levels so I'm not that worried.