Really sorry about that! I did a small bug fix right before I had to go somewhere so I didn’t test my newest build properly and set an flag incorrectly when exporting. The web build should work without issue again now, I uploaded a new build and know to avoid the issue in the future.
About the malware waring: I don’t think there is much I could do against that, as any software that didn’t get an official (paid) certificate is usually threated as such. It’s the reason why I always provide web builds. The only thing the antivirus could have a problem with is that I create and edit files for the save-game and created levels, but it’s not really possible to have either feature without doing that.
Either way, sorry about my slip-up and hope you will give the game another shot!