Difficulty settings

Just uploaded V 0.3.0.

Changes

• Players can now choose difficulty at game start
• Tweaked UX of gallery screen
• Opponent decks were fine tuned / reduced
• Added tit-fuck card
• Made buttons prettier

Try it out and let me know if the difficulty settings seem right, or need more fine tuning :-)
I'm currently working on allowing the player to change the deck between levels, as well as adding more levels. This will probably take me a few weeks (I only work on this on weekends)