Large update and taking feedback

Just finished large update I've been working on for a week and a half

after reading many jam comments I decided the most important things to add were more upgrades enemies and bosses.

I added:

• over 10 addition upgrades, allowing for better and more complex builds
• 2 new bosses, each with unique attacks
• a new enemy that splits on death
• many features to increase the overall feel of the game such as tween progress bars
• I've decided to remove the difficulty modifier indicator in favor of a boss timer; difficulty modifier still exists though
• added new icon and loading screen
• added 4 or 5 new soundtracks 

overall, the game has much more content and feels more polished. If you have any ideas for new abilities, enemies, or bosses (or anything else really) comment them on this post or game comments and, as long as I can code it in a reasonable amount of time, I will add it.