pythonDefender - ALPHA 0.1

As of right now, the game is still in an alpha stage. I plan on adding sound to the game. There is an upgrade shop the player may open at any time and spend the credits they earn throughout the game. Currently there is no break between the waves, and I see no reason to add any, as it keeps the game tense and fast paced. The waves get increasingly difficult, though there is a long interval between waves 11 and 21 where little will change. The starting screen is bare bones minimum. Planning to move a large chunk of the code to functions to clean up the source. Leave any comments, praises/flames as you see fit. INSTRUCTIONS: Right arrow --> RIGHT Left arrow --> LEFT Space --> FIRE WEAPONS 's' key --> OPEN/CLOSE PLAYER SHOP mouse button--> SELECT UPGRADES IN PLAYER SHOP 'q' key --> CLOSE GAME