Base Defense

A co-op mod for Half-Life 1 with RPG elements. The idea of the game is pretty simple - various monsters attack a tower, and the players have to fight them off. Every monster you kill earns you money, which you spend on buying and upgrading weapons and on items from the demon merchant. When a player dies, their points are reset.

There are three characters in the game: Rushing, Religious and Provident. Each character has several unique abilities. You select abilities with the F1, F2, F3 keys and then activate them with the middle mouse button.

Rushing — the attacker. Has a vampiric aura that restores health as you hit monsters.
Religious — the mage, has a health regeneration aura.
Provident — support, helps other players with supplies and can build turrets.

In Base Defense you can level up and boost some of your player stats (movement speed, attack damage, etc.).

Keys:
Z — quick phrase.
X — invisibility. You have to stand still to activate it. Attacking makes you visible again
C — player stats.
V — quests.
B — skills menu.
N — use mana.
M — use a medkit.
G — give a nearby player $250.
I — inventory.

If you have anything bound to these keys in Half-Life, you should remove those binds.

There's a demon merchant in the game. You can buy various items from him and upgrade your weapons.


You can also find a book like this one. It lets you summon a huge Gargantua, which you'll then have to fight.


Links:

• The game on Steam
  
• ModDB
  

Installation:
Copy the contents into the root Half-Life folder (where the hl.exe file is located)
For example D:/Games/Half-Life or D:/Steam/SteamApps/common/Half-Life

If you're an evil pirate and don't have a couple of bucks to buy Half-Life 1, do the following.
Copy the contents of the archive into the root directory of your Half-Life and run hl.exe with the following parameters:

hl.exe -game bdef

You can create a bat file or a desktop shortcut.

Screenshots: