It's an okay card  battle game.

Found some sort of error when I tried to upgrade the Blightriders card during the 'only 4 cards in deck' challenge:

ERROR in action number 1

of Draw Event for object oCardDeck:

Variable Index [6] out of range [0]

at gml_Object_oCardDeck_Draw_0

gml_Object_oCardDeck_Draw_0 (line -1)