This update is a big one, compared with the ones before it! I added a bunch of new systems:

• Particle effects for basic on-hit graphics; this is about as simple as particle effects can get, but it will be expanded over time
• Shaders for visual feedback like flashing and outlining, including a prerendering system that allows me to apply shaders to groups of sprites as if they were one surface
• Loot generation - there are only a few weapon types now, but the infrastructure is there for easily adding new item types and rolling random drops
• Inventory - items are dropped on the level map, display info on hover, and can be picked up; items in the inventory can be moved around, equipped, or sold for extra XP.

And made some changes to existing systems:

• Enemies now come in waves instead of a constant barrage, with a brief respite in between for opening loot orbs and equipping your spoils
• I created a slightly bigger map that I think accommodates the wave format a bit better.

The next couple of things on my to-do list are:

• Add rarities to the loot generator (it currently only rolls common items with base stats), including a handful of random modifiers for rare items
• Implement a composite-sprite system so that wings, hulls, and engines can be treated as separate equipment pieces with associated cosmetics