If you don't know how to change this settings exist 2 ways. Simple and slightly more complex. Simple: go to game root folder and open file AlienShooter.cfg with notepad or other text redactor. https://prnt.sc/WAKOP6dvX5Wl In there you need option VSync https://prnt.sc/mANoSDBqRfbm . Type 1- VSync is ON, type 0 - VSync is off. This way is work if your monitor have 60Hz refresh rate.

If your monitor refresh rate higher then 60Hz. Open NVIDIA control panel Click on Manage 3D Settings Click on Program Settings Select AlienShooter in the dropdown menu. If you can’t find it, click on Add and find AlienShooter.exe. Menu Max frame rate and use this settings https://prnt.sc/HPbE_D2VQ28z . This option is working and fps really locked on 60fps and game physics does not break. But may appear screen tearing.

On AMD GPUs you also can did same FPS lock. Go to Radeon Settings then Games. Find AlienShooter.exe and set max FPS for game. I don't know exactly how to set it up on GPUs from AMD because i have NVIDIA but i think it's about the same.

If you know/find another working way for lock FPS tell me, and i add it in giude.