Don't know whether it's my machine, windows sucks - that keys buffer delay bug... Framerate fine, but controls barely responsive. R sometimes not working, also fire. I like the landscape very much, would rather explore it than die so quickly.
I just tried it out on the Web version. Everything seems to be working perfectly. No delay between weapon swaps and reloads/firing working fine. Sorry that your experience wasn't the best.
I know you didn't ask or anything but I rebuilt the game for Linux if you would still like to try it out without problems. If you do could you let me know how it works and maybe rate the game? Thank you!