Mostly under-the-hood code changes. A few things that may be noticeable to note;

• Stage introduction title graphics now use improved number graphics that more closely match the theme of the text. Also, some stages now have corrected numbers for their titles.
• (some) double turrets now have recoil animation
• Slight increase to horizontal pan, which effectively is an increase to player horizontal movement speed.
• Adjustments to level loading so loads may appear slightly smoother
• Lighting system rework (may have broken lighting on some stages)
• Improved tile textures