Edit: I forgot to say: Thank you for help!
You are more than welcome 
If it did, it was not intended to be running any IIS stuff.
Might be worth looking at your installed Windows components and just see if it is installed, if it isn’t something you are familiar with, or need, you could remove it, or just use “Build”.
Any advice as to how to avoid lag and/or what drives lag and long load time? There is quite a lot of different things that going on in my block breaker so hard to pinpoit. All sound effects are at 70% quality, overridden for webGL and “compressed in memory” as some webpage reccommended for medium sized files being played often. I have many images (backgrounds and such) but they only account for 6 mb of space so it should not take forever to load.
That’s a fairly broad question, as there are a number of factors to consider in your specific case. Firstly, I don’t know what the server specifications are for the GameBucket.io server, this could be a factor if the server was getting a lot of traffic/requests (I doubt it is). Internet connections… I think I’m on a 100mb line here and get typically around 60mb… your game took about 3-4 minutes to load for me… initially I was counting, after 110 I stopped counting 
Most likely the size of your assets is a significant factor but also the actual design of the game itself, and this gets covered in Glitch Garden… but as an example, and this isn’t a criticism of you or your game, just an example;
I clicked on your link and after a few seconds was presented with the grey square as the GameBucket.io site responded to me request. I am familiar enough with the student games on this site to know that this is fairly normal, so I patiently waited. As I mentioned above, I started counting the seconds just to see what the lag was like. After 30 seconds I was bored of counting the seconds, but was trying to help so continued, at 100 seconds I was REALLY bored of counting the seconds, at 110 I stopped counting the seconds and flicked to another tab whilst it carried on doing it’s thing in the background.
This is actually quite a big problem, if you share your game with people (fully appreciating you are working on it etc, this is again just as an example) they will have certain expectations, as you can see from my text above, after 30 seconds I was bored of waiting. There was nothing on the screen to indicate that anything was actually happening. “Should I go back and click the link again?”, “Maybe I should refresh the page?”, these are thoughts your players may have and in this case, by doing so, would only make them have to wait even longer.
So, how can we resolve this? Assuming at this time that we are unable to determine whether the server is slow, or whether there are any networking issues, or whether we could improve the size of your assets, the one thing we could change is your game architecture.
At the moment, the player has to wait for the firs scene to load - it’s loading a lot of assets back there, just for a screen with some buttons to press and some music… again, this is covered in Glitch Garden, but you could add another scene to the build order, perhaps a very simple background image, a title, and a little piece of music - nothing big, but considerably smaller to load than the main menu. You would need to add a check for when things are ready, but then flip to the main menu once the loading is done.
This way, whilst we haven’t really changed anything in the background, the player is at least greeted by your game, they know at that stage that it is working, they get a screenshot that sets some expectation of what they are going to be able to do - so make it cool or mysterious, so that they will be keen enough to hang on for those extra seconds to see it, your music will be a nice distraction (as long as that loads quickly!)… then fade out perhaps gracefully to the main menu.
At this stage you should be able to achieve this reasonably easy, you can obviously create a new scene, you can add the title, the music, maybe you need to find a code example or ask for help for the loading the main menu when ready, or the fade, but having seen what you have already added to your game I don’t suspect this would be a big challenge. Equally, you could skip ahead a few lectures to just see the bit about the loading screen and then come back 
After this, if it were me, I would probably be looking at asset sizes next, and whether the code is efficient.
Is it possible to disable the full screen button on gamebucket in script? The game is not and will not support full screen)
My understanding of the GameBucket.io website is that it simply returns your index.html page in an iFrame. As such, if you have a look in the /TemplateData directory that you have after building and looking at the index.html file, you may be able to make some changes to it there
The ball is the object that lags most,
I can’t say that I really noticed that when I was playing, it did a little at the beginning, but seemed okish after that…
it has the following code attached to it in fixedUpdate to regulate speed
Ironically, this probably isn’t helping. FixedUpdate() is necessary when you are using forces and physics. You can use Update() and then to allow for the time difference between frames and Update calls, use Time.deltaTime
it has a continous collision detector which I have heard increases cpu demands, but I sort of hoped it wouldn’t increase it enough to break the game.
It will increase demands, but lets be realistic, this is one ball moving and the paddle moving around the screen, this isn’t going to be a problem. In fact, not having continuous set would introduce potential other issues, such as the ball not registering collisions with blocks, or worse, the paddle!
I hope the above helps, and those links are also listed below for convenience.
You have a nice game coming along here, well done, you’ve implemented a lot of cool ideas, keep it up.
p.s. typo on the menu screen “Achievements” 