Subvein is a free online multiplayer shooter. What makes it unusual is that it's a top-down 2D game!
Like many online shooters, you have some control over your player - you can buy and upgrade weapons, and there is a RPG element of developing your skills as you progress. Every kill you make gives you experience points you can spend. The more your play the stronger and more resilient your player becomes.
Subvein is played one team against the other, and is essentially a capture-the-flag game. There are a variety of maps to play, and they all have a 3D element - although the game is top down, there are stairs and levels too.
The graphics are pretty neat, with both the players and the environments being distinct and the lighting and blood effects are cool. The only issue is that bullets are probably too small, so in the heat of battle you really can't tell what's happening. Currently games are not leveled, so you can find yourself as a newbie up against some very powerful opponents, which is off-putting!
This is still in a relatively early form, and still very much in development, so getting involved in the community can have an effect on how it changes.
If you enjoy online competition and old school top down shooters, you'll enjoy Subvein, although it needs some balancing of gameplay. At the moment it very much feels like a hardcore game for hardcore players.