your not crazy that shouldn't be happening. what are your system specs if you don't mind me asking? that quite unusual as performance is much improved from previous version due to a few important improvement i made. if you have time i could guide you through using the web console to help figure out what going wrong.
On my last point, my computer seems to be acting weird for files in general rn, need to look into that but I got the downloaded version running and it works fine! So its experimental and website versions that still run bad...
I'm not super technically inclined, so I hope this pic helps answer some of the questions! Opera is eating most of my memory rn but my CPU leaps into space when the game launches (This was it loading a save in a cave) 
11 days ago(+1)
that's great! honestly I'm not a terribly big fan of opera, as it does some weird stuff. have you tried it on a different browser? either way I'm glad the downloadable version is working for you ^_^ the worst load time is in the new cave area, but that's only because it loading over a thousand frames of animation broken up between 20-30 different sprite sheets. the boss is so large its sprites had to be broken up a lot more.