Well if you want a honest critique I'd have to say as a guitarist that the playing was pretty good and the energy was there. The drummer missed a few cymbal strikes and I couldn't hear his double bass strikes very clearly which led to "X" feeling a bit slower than the original. But the double bass could just be because of the quality of the video, and the cymbals are just very minor mistakes.
The singer is ok but his voice is very low compared to Toshi. I like that he doesn't try to sing as high as Toshi if it's out of his range because that would just sound like a train wreck but then again these songs just don't sound the same without a high soaring voice over the music.
All in all I'd probably give this like a 7 or 8 out of 10.
Keep practicing and if your singer can practice to improve his range to sing a bit higher that would make you sound all the better. I'm glad there is now a tribute band for X in my home country and if you ever manage to get lost gigging somewhere near Kiuruvesi I'll certainly come to your gig!