Here are a couple of examples: Balls Brothers, OFFS3T game, The Sequence, Color Balls... These are not all games that don't load.

These are working for me via Ruffle, are you loading them with NG Pjayer?

Yes, I run them through Newgrounds Player.

Survival Horror - Newgrounds Rumble

I have done the requirements and I have proof of completion but it won't unlock on the website.

This game loads the intro and then freezes at a grey screen. Tried both NG player and Ruffle with the same result.

incidentally, i've also been going through gamezhero games lately, and have been stuck on this one specifically:

seems like when launched via newgrounds player, it's constantly stuck on loading.

meanwhile when launched via ruffle, it loads, but after pressing play the game's stuck on a black screen.

there's options in the top right corner which allow to "pause" the screen, and the pause menu works fine, meaning it's not like the game isn't working; but either the game itself has broken, or there's a second non-visible loading screen that takes way too much to load? idk

Do medals work in ruffle???

i haven't tried any of the games you've listed, and the other gameszhero games i played so far have worked just fine with newgrounds player.

but when they don't, trying to use ruffle should work.

unless it's a specific case, medals should work with it as well, in general

I have a couple of broken medals to report, both in the game "Epic Battle Fantasy 2."

The first medal is one you earn by finishing the game on the "hard" setting, which I did, yet I never unlocked the medal.

The second medal is one you earn by getting 5000 or more points in one of the mini-games available in the menu, which I also did but never got the medal for.

I took a screenshot of the issue with the second medal to showcase the error:

(I have no reliable screenshot regarding the problem with the first medal. I didn't take a screenshot of me beating the game on hard difficulty as I didn't think to do so until I returned back to the menu of the game and then realize I didn't actually get the medal for whatever reason, the only screenshot I could take about the first medal is one showing my last save on the "hard" setting, which is 66% through the game)

Anyway, I would love to have these issues fixed, if it is possible. I'm not knowledgeable enough to know what the problem is, so help will be appreciated!

Update: this game works fine if launched with NG Player using Opera browser. On Chrome and Firefox it freezes at the intro as I said, only Opera works. Medals work fine as well.

Also, I tried playing Orange Roulette but medals don't seem to work on any browser, at least for me. Pop-ups appear in game but the medals don't unlock. However there are still few people unlocking medals as of today, I wonder if they work using a specific browser? Also I don't really understand why the game is considered "insecure" and needs to be played on another tab. I've seen several medal games in that state, and all of them tend to have issues with medals.

Update 2: Orange Roulette medals can be unlocked by adding "/format/flash" at the end of the URL, which makes the game launchable via NG Player. However, this method does not work for other games that too are "insecure" and forced to be played on another tab, like Antumbra or You Are Slime.