Notice
Heaven's on Fire is an example of how a good rock song can be very simple to play. The intro and the verse are played by two guitars with the basic root-fifth-root power chords, except where Riffs A, B and C come in. Here, one guitar plays the power chords while the other plays Riff A a la Chuck Berry, and then accentuates the bass note movement with single notes and some bends at Riff B. The first chord we hear in the intro starts on the upbeat of the fourth beat of the measure and is tied to the first beat of the next measure. This is called an anticipation.
Hit the chord on the "and" of four, and then hold it through the first beat of the next measure. This figure occurs many times thoughout the song.
The characteristic Kiss sound in the chorus is the slide from the Bb5 to the C5 chord which serves to enhance the vocal.
The bridge has a tricky chord slide in the 3rd and 4th bars. Make sure you hold the Bb5 and A5 chords down tightly, since it is harder to slide a chord down the neck than up.
The instrumental solo works well because of the contrast between the single bass note figure and the high arpeggiated chord. This arpeggiated figure is harder to play than it sounds. Practice it very slowly at first, and then build up to speed.
If you are looking for an easy song to work out with a band, this might be a hot one.