I liked Endgame but honestly, I feel Mustaine is starting to show his age ever so slightly. That raw undiluted energy seems to be missing on Endgame. The album definitely showcases Megadeth's strengths - technical instrumentation, blazing fast solos, intricate riffs it's all there. The Megadeth heritage if you will is definitely present but what isn't present as much is Mustaine's angst, frustration, paranoia - all the individual characteristics that make up both Mustaine and Megadeth, and that ultimately gave Megadeth its unique character.
I guess it's almost like playing music but not feeling what it is you're playing. That is how I view Endgame - on its face it has all the musical elements of a great Megadeth album but the angst ridden atmosphere is missing. It feels as though Mustaine seems a bit too content with reality, and is simply writing and recording new music to appease the Megadeth fanbase rather than to quench his own inner flames and demons. Something that I felt at least seemed more evident on earlier Megadeth albums.
In a way, I feel Endgame is slightly forced. It seems as though Mustaine just wants to recapture the essence of what it is to be a thrash metal guitarist but without realising that part of what made Megadeth so unique was the emotional battles he was fighting - whether it was his undying addiction to drugs, his motivation to be better and more successful than Metallica, his family problems etc.
What we get instead is a Mustaine who is at peace with himself - and I do not blame him for finding God, becoming a Christian and living a clean life. Ironically, however, it's Mustaine himself who says (in his book) that you cannot have your cake and eat it too: you cannot be part of a successful musical entity such as Megadeth and yet live the normal suburban family life. According to Mustaine it's like two worlds colliding, you have the sex, drugs and whole rock n roll life style on one hand, and the responsibility of keeping a marriage together and being a father to your children. It may be manageable when it's just you and you don't really need to take care of anyone else around you - and if you're found dead then your epitaph will be that you lived life on the wild side to the fullest but not when you have other people to take care of and look after.
I think Mustaine is well aware of that and it is perhaps unintentionally showing in his music. He plays music because he has a newfound appreciation and love for playing his guitar and belting out both new songs as well as classic songs from Megadeth's back catalog. However, inevitably the writing and recording of new material has a different tone to it nowadays - I think it's harder for him to draw on current personal experiences and canvass them in that snarly aggressive tone.
That's just my view of things but this is not to say I am criticizing Mustaine - rather I think it's something Megadeth fans, including myself, have to accept that Mustaine has for better or worse transcended those turbulent drug induced 'daze'. That he's not only trying to be, but again for better or worse, in fact is a changed man - as difficult as it is to believe or accept that.
I think taking all of that into account kinda puts in perspective why an album like Endgame may sound a tad, lifeless for lack of a better term.