The biggest problem with FPS is having a quick save function. It's not necessarily a design problem, but it's more a me problem, as I can't stop myself from savescumming, and will just ruin the experience for me. I can't have that comidity that easily accessible. I wish more FPS had checkpoints or other saving systems. But even FPS with checkpoints sometimes have very awkward checkpoints. Having good checkpoints is also a skill an experience dev must have. I know most people don't agree with me so I don't bother pushing it on people.