Aero Chimera - Troubleshooting

[CaptainKraken]

Ahoy all!

I remember really enjoying Aero Chimera back in the day, but now I cannot for the life of me get it to run properly.

Whenever I launch it, it only runs at 30fps (half speed).
I can turn on vsync to get it to run at the full 60, but the extra lag that introduces makes a game like Chimera practically unplayable (or at least, thoroughly unenjoyable).

I was messing with a bunch of settings the other day and managed to get it going at 50 fps, which was good enough for me, but I cannot replicate that result now :/

I was wondering if any of you have had the same issue and/or been able to solve it.
It's been several years since the issue cropped up. I did reach out to SAS back then, and he said he was aware of it but didn't know any fixes.

Shame, too, since Aero Chimera was one of the best freeware bullet hells at least that I've played.

If anybody can help, it would be very much appreciated.
Thanks!