Blue nodes give you Data. Yellow nodes - Credits.
Green nodes are your personal toolbox with effects ranging from basic defense to creative rule bending.
Red nodes are hostile. They will cause you all sorts of trouble.
And then there are the purple ones. The Cores. Mini-bosses, each with its own unique ability or victory condition. Almost every level has one.
Nodes of all the types are mixed together to create levels with endless opportunities for combos and synergies. And since this is a deckbuilder - you get to pick those nodes yourself!