Case doesnt matter so long as its big enough to house a decent gaming GPU in it, so long as the motherboard can fit a modern GPU in you should be ok. That processor might be able to handle games ok depending on which model it is and would need some more RAM (8GB minimum I would say). I was recommended a AMD ryzen 5 3600 & they are incredible for the price but im waiting on new CPU & GPU announcements in next couple of months. The Power Supply usually has the model and details written on label on it.All economy-tier manufacturer stock parts in an Acer case in early 2010s style. I do like the case, it's got a classy aged architecture appeal.
AMD processor, quad core at 3.4ghz. Can't remember offhand but I think it's FM4. Sounds good except embedded graphics, ati apu, definitely nothing fancy. Embedded audio, but I'm partially deaf so I don't care too much about that.
4gb ddr3 ram. Basic speed. Max 16gb on motherboard.
Single white label hdd, 500gb. Sata 3.0, with room for another. The hard drive looks good, I'm just concerned about the age. I already created an image backup (whole reason I got the machine was the software!). Wanna replace it and use the old one for non-vital storage.
Haven't looked at power supply, not even sure how I'd check it.
New GPU is the main thing you require with some additional RAM and maybe a new CPU (so it doesnt bottleneck the GPU).