Performance improvements
Everybody likes to put “performance improvements” in their release notes, but I really have done quite a lot of optimization this release, and you're likely to see a meaningful difference.
Graphical improvements
Better graphics for pits, lasers, diamonds, and slidey blocks, and minor improvements to various other objects.
Spruced up the title logo a bit.
Editor changes
Some of the items from the secret levels are now available in the Editor after you complete those levels.
The portable remote control item and the deactivated grill are now available in the Editor. To unlock each of these, complete any Level Pit level with that item in it. The deactivated grill is available by right-clicking on a normal grill.
You can now choose your level's appearance and background music from the new "Info" window in the Editor.
Added a bunch of cosmetic floors.
Added some variants of the slippery floor.
You can now place enemies over pits if you like.
The clone machine can now clone almost anything.
You can now right-click on the rolling barrel to change its direction.
Level Pit changes
When you complete a level, your time and score are now optimistically shown right away on the level page and on the leaderboard, without waiting for the server to verify them.
The Search function has been overhauled and might now actually be useful. You can sort and filter by various criteria, and the search box matches on author name as well as level title.
Bug fixes
Fixed a bug where the tile picker in the Editor wasn't usable if the window was too narrow.
Fixed a bug that could cause frame stutters on some hardware.
Fixed the text input boxes being generally janky.
Fixed a bug where the Level Pit Timer would reset to zero when reloading from a save point.
Fixed a bug where flying around in space could cause the sound volume to go funny.
Fixed an audio bug that caused chains of explosions to not sound right.
Fixed the search results in the Level Pit being cleared when returning to them with the back button.
Fixed a bug in the Hall Of Plasma Orbs where the starfield effect would sometimes glitch out.
Fixed some visible pop-in on the main menu background.
Fixed a bug where the dark star doors would sometimes fail to open.
Fixed a bug where the first World 10 cave would sometimes not draw its background terrain.
Changes to levels
Minor layout adjustments to a couple of the World 1 levels.