First, you will need your game keys. Check your purchase email for the keys. If you don't have that email, then email support@knucklecracker.com. Include your purchase email address and/or other information entered during purchase. That information is what I need to be able to lookup your key. Without your key, you won't be able to install and use the games again.
To download the games again, you can go here:
Creeper World 4
http://knucklecracker.com/creeperworld4/redownload.php
Particle Fleet
http://knucklecracker.com/particlefleet/redownload.php
Creeper World 3
http://knucklecracker.com/creeperworld3/redownload.php
Creeper World 2
http://knucklecracker.com/creeperworld2/redownload.php
Creeper World
http://knucklecracker.com/creeperworld/redownload.php