Around 1 hour 4 minutes to beat, but started on the harder Classic scoring system, and ran out of points to buy continues with. The default aiming sensitivity feels pretty bad and difficult to see reticule on screen often. For some reason I got to the final boss on the Series X version on my first try with the harder scoring system the game defaults on. I did beat this version on the Modern scoring system shown here, but my score was nearly 30,000 points lower. It seems it was easier to aim on the Series X version but couldve just been the controller I was using. Runs great on the Yuzu emulator. My Series X playthrough and first attempt are also both posted up on the channel.
One thing that works very well in these games is mashing both the reload and fire buttons at the same time so that you never have to stop to reload. Reloading doesnt really cost you any time if you are constantly firing. Ive exploited previous versions of these games by setting both buttons to turbo.
The True Ending is based on getting over 60,000 points I believe, which is very easy with the modern scoring system. With that setting its easy to afford more continues, which cost points to unlock.