Remove link to PlayForm

[bvssvni]

This project used Piston initially, but went away from it.

[rolandasb]

Which game should take its place?

[bvssvni]

I don't think anything besides Sea Snake Escape works at the moment, and it isn't a good looking game.

@stjahns Do you have something we can show on the front page?

[rolandasb]

In worst case I could replace last block to big "More games" button...

[stjahns]

@bvssvni - I don't feel like the 'animation viewer' is quite ready yet (http://imgur.com/2hCBCgM), but when I get back from vacation in a couple weeks I want to do a quick port of one of my Ludum Dare games, "it shouldn't take more than a couple days" ...

[bvssvni]

@rbrs @stjahns We could use a screenshot from https://github.com/PistonDevelopers/skeletal_animation_demo now that it works.