Portals [Alpha 27]

This was such a fundamental improvement for the game it got me thinking about teleporters. I'd avoided them because,

1. There's no floor layer in Unending.
2. Where would they send you? Especially if there's an odd number of them.

My compromise is the Portal. Walk into it and you pop out the other side, moving 2 squares. If there is another Portal directly ahead, you pop out the other side of that one instead. You also swap places with any piece at your destination - I'll leave it to you to figure out how to tele-frag a piece.

There are 14 new portal puzzles to try on a branch of the puzzle campaign map.

This update also includes various bug fixes and polish.

A mac version will follow once I'm satisfied this update is stable.