Here are 4 games I have created with Construct.
They are reasonably polished, and show off Construct's various capabilities. I'm currently working on finishing TowerClimb however, which is my largest and most complex game to date. The alpha version is playable, as Arsonide linked above, but It's a year old and is MUCH less feature complete and polished than it is now. A lot of people still enjoy it nonetheless, which is what made me take it to the next level.
Also, I would suggest checking out The Iconoclasts by konjak:http://www.tigsource.com/2011/03/30/wip ... onoclasts/
It's a highly impressive example of a gba-style adventure platformer. It's a 2 level demo, but it's polished to perfection.
Finally, a game made by my brother Quazi and I:http://gamejolt.com/freeware/games/arca ... atch/3161/
It is the only polished,full featured 3d game made in Construct. It even has a 3d editor so you can design your own characters. The gameplay is simple but the graphics show you how far you can push Construct into doing 3d though it's insanely powerful event system and sprites alone(no 3d box or 3d model plugins).
And yea, the community is very small. Tiny even.