It might be the new stuff is leaning on a heavy guitar sound more than the old albums, so there’s less pressure to write epic leads and harmonious stuff or even simple rhythm riffs (which sound better in 8-bit). You might argue that ’limiting the bits’ puts your musical creativity to a test, keeping in mind of course what sounds good in 8-bit still needs to be rich enough to sound full ’on stage’.
I was hesitating to analyze Bodom with Megaman soundtracks (it would get really long and deep), but they share something very similar in the vibe of the melodies, both being very beautiful but still pumped with adrenaline in many different ways, Bodom is just the darker version. And what’s common about them is playing guitar-written stuff on keyboard.