0 A.D. Alpha 5 Released!

QuoteNew features in this release:
Gameplay:

New civilization: Iberians
Much improved enemy AI named JuBot (thanks Jubalbarca)
Random map scripting (thanks historic_bruno)
Unit promotions (thanks fcxSanya)
Improved formations (thanks Badmadblacksad)
New map: Acropolis II, in which the Iberians face off the Hellenes (Screenshot below)

Graphics:

New shader-based renderer mode, to support new effects and improve performance
Improved lighting for warmer and more vivid colors
Particles - fire, smoke, construction dust, sparkles near mines, falling leaves
Terrain decals - smoother building foundations on bumpy terrain
Hidden units are visible as silhouettes
Various performance improvements (thanks in part ortalo)

GUI:

Idle unit button (thanks veprbl)
Unit control groups (thanks Badmadblacksad)
Unit selection limit raised from 40 to 64
Map setting editing in Atlas (thanks historic_bruno)

Art:

Eye candy - Rope bridges, River bridges
New loading screen images and tips

Audio:

New sound effects: Unit selection, building destruction
New music tracks: The first ones of what will be an entire soundtrack remake

Room for improvement:

Many unit stats are still unbalanced.
Many planned gameplay features are not added yet: There is no research, no auras, no formation bonuses, no stances, no settlements and territories, etc.
Many bugs and small missing features.
There is no multiplayer matchmaking service. You have to connect by IP address. (More convenient ways may be implemented in the future).