Is the Nvidia GTX 745 with 4 GB GDDR3 dedicated RAM good enough for casual gaming?

Hi. So basically a computer was ordered for me that comes with Nvidia GTX 745 that comes with 4 GB of dedicated video RAM. The computer was around £500 (I'm not exactly sure how much it is). I think it designed to be a gaming computer. Whenever I search up this graphics card, not enough information really comes up. I have looked at reviews of it but I don't understand anything (I'm not really a computer expert). I just want to use this computer for casual gaming. Not hardcore gaming. Like I probably won't be using this computer to play like the high end detailed games there's out there. A few examples of the games I want to play are:
Minecraft (obviously)
Portal 2
Bioshock infinite
Castle crashers (steam edition)
Left 4 Dead 2
and maybe some others since the computer comes with a 1TB hard drive so I can download more. So is this graphics card good enough for casual gaming. Like the examples above type of games and not Crysis 3 type of games.

The specs of the computer:

4th Generation Intel® Core™ i5-4460 processor (4-cores, 6MB Cache, @ 3.1Ghz and up to 3.4GHz w/Intel Turbo Boost

Windows 8.1 (64Bit) English

NVIDIA(R) GeForce(R) GTX 745 with 4GB DDR3

8 GB RAM

1TB (64MB Cache) 7200 RPM SATA 6Gb/s

Guest

Eww.

No, Castle Crashers should be fine, Minecraft may get 30 fps on the lowest settings but that's about it.

I recommend getting another GPU if you have the cash, Bioshock Infinite looks stunning and you don't want to play through it on the lowest settings, barely scratching 10 fps

The Man

http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+745 benchmark of 2200 this gpu won't get you fair with causal gaming. Everything except Bioshock will run at medium( Minecraft) to max(left for dead 2) at 60 fps.
I would get the R9 270 that uses GGR5 instead of GGR3 and is twice as powerful as your gpu in the future if you want to invest 150 dollars in a gpu. Your gpu that came with your computer is worth as much. And Alienware is overpriced. It is cheaper to buy parts then go to a technician and pay them to assemble it.
http://videocardbenchmark.net/gpu.php?gpu=Radeon+R9+270&id=2766

Edward