Version 1.18.0 (8/29/2018)

Added difficulty dropdown (previous difficulty is now 'hard' in the dropdown)
Made level 1 harder again
Removed level 8
After placing your last tetrad, the enemies no longer spawn immediately. There is one more click to spawn enemies, and text displays reflecting this. This allows undoing the last tetrad placement.

Version 1.17.2(8/26/2018)

Make level 1 easier again

Version 1.17.1(8/26/2018)

Rotate music tracks every 3 levels instead of every 6 levels

Version 1.17.0(8/25/2018)

Fixed typo in hint 3
Move the level that was previously 7, 6 spots later
Modify level selector so that it reflects the current level, fixing a related bug

Version 1.16.0(8/23/2018)

Add hints that display between levels

Version 1.15.0(8/22/2018)

Change tetrad targetting so they try to target enemy closest to end, instead of going based on spawn order
Made level 1 more difficult
Made level 2 easier

Version 1.14.1(8/20/2018)

Update build tetrad noise

Version 1.14.0(8/20/2018)

Move date that was erroneously put on changelog line back to Version 1.13.1 line
Adjust level 14 shape
Replace lives counter with level counter
Label spawn point as a waypoint
Adjust enemy counter so that enemies stop being counted when they die, not when they spawn
Fix undo button so that enemies don't remain rotated when you undo

Version 1.13.1 (8/19/2018)

Adjust formatting of HTML table on main page

Version 1.13.0 (8/18/2018)

Reduce damage of L and J tetrads
Rebalance some of the levels
Add new levels
Fix 'undo' so that undone rotates appear in correct orientation in 'coming tetrads' screen region
Change first letter to lower case in "(... and more)" message
Add counter for the number of enemies that have not yet spawned
Remove large overview image from how to play section

Version 1.12.1 (8/10/2018)

Add date to version 1.12.0 in changelog

Version 1.12.0 (8/10/2018)

Changed mobile tower placement so second click has to be closer to first click to cause placement
Changed graphics load order so critical graphics load first
Add some more levels

Version 1.11.0 (8/8/2018)

Added support for undoing a tetrad placement
Added buttons for undoing and rotating tetrads to simplify mobile play
Added button to restart the level

Version 1.10.0 (8/2/2018)

Added better mobile support:Touch once or touch and drag to preview tetrad position; touch ghost tetrad again to confirm placement. Triple finger touch the screen to rotate tetrad

Version 1.9.0 (8/2/2018)

Improve documentation on how to play page.
Fixed bug where O tetrads would not target any enemies if all enemies within range were slowed.
Added dates next to versions in changelog.
Added text that says how many tetrads you have to place that are not shown in the preview section.
Added a grid to the game to make placement easier.
Adjusted sound so that sound being turned off is respected if you navigate away from page and back again.
Adjusted sound so that sound doesn't begin to play until the level starts.
Silence defeat / victory sounds when music for next level begins to play.

Version 1.8.0(7/31/2018)

There is now no timer for placing tetrads, and you have a finite number of tetrads. Enemies only begin to spawn once all of your tetrads have been placed.

Version 1.7.1(7/21/2018)

Add feedback email address

Version 1.7.0(7/19/2018)

Redesigned html; tetradefense.html and index.html are integrated together, and changelog is moved in to a separate page
Swap levels 3 and 6

Version 1.6.0(7/18/2018)

Added dropdown menu to make level switching easier
Added radio buttons to allow turning music and sound off separately, and to make both easier
Small amount of cleanup to pathing code
Updated user facing terminology - "big tetrad" to "mega tetrad"
Removed one level (what used to be level 4)
Integrated in a third track. Now each track plays for 3 levels

Version 1.5.0(7/14/2018)

Save up tetrad builds instead of only starting the timer once the tower gets built
Adjust tetrad damages (Increased damage of tetradO, increased damage of tetradI)
Moved how to play section to it's own page, and expanded it
Adjusted some of the levels to make them more difficult / easier
Added option to turn off music, and/or all sound

Version 1.4.0(7/13/2018)

Adjust down volume for failing to build
Fixed large J / L so that they still attack multiple enemies
Change appearance of large tetrads so they're composed of larger blocks
Replace patreon link with paypal link

Version 1.3.0(7/7/2018)

Tetrad that you are placing appears more faded if tower timer is not up yet
Fix the level indices that are displayed on the win / lose screens
Make it illegal to place tetrads over last waypoint; have tetrad display red when attempting to place over any waypoint
Start at whatever level you want to. For example: (replace 5 with whatever level you'd like to start on)
Defeat sound effect
Add numbers to waypoints to make path more clear
Adjust O tetrads so that they will prioritize attacking enemies that are not slowed
Sound effects for placing a tetrad, for a tetrad failing to get placed, for a combo being created.
Adjust L and J tetrads to be able to attack multiple enemies at once
Adjust all tetrads to attack slower and generally to rebalance them
Adjust some of the level difficulties

Version 1.2.0(7/3/2018)

Victory sound effect
Have win / lose screens between levels
Redo and add levels
Fix bug where placing tetrad on top of first waypoint causes exception
Add second music track
Change tower timer so you're unable to build at start of level
Retry playing music every 100ms if browser declines to allow it to load

Version 1.1.2(6/26/2018)

Fix changelog formatting

Version 1.1.1(6/26/2018)

Turn audio back on (accidentally turned off)

Version 1.1.0(6/26/2018)

Adjusted enemy difficulty
Rewrote first three levels, removed fourth for now
Fixed bug with pathing and "blackpoint" spaces that are blocked at start of game.

Version 1.0.2(6/26/2018)

Major rewrite of pathing to fix miscellaneous bugs
Make enemies draw more "centered"
Reverse order of versions in changelog

Version 1.0.1(6/23/2018)

Fixed pathing issue where newly spawned enemies wouldn't path correctly until a tower was placed
Fixed Patreon link
Added changelog section

Version 1.0(6/22/2018)

Initial release