I havent played it yet, however I would like to ramble about it, so maybe my rambling will be of use.
First you may have played its forebear(s) Battle for Moscow and his follow ups with VPG. A simple introductory ruleset (explained below).
Thunder in the East takes that introductory wargame concept, which weighed in at a dozen or so pages, book sized map, plus half counter a sheet which covered a single eastern front operation and turned it into a game that covers all of the Eastern Front and later ETO.
The price for that is a 88 page rulebook of fairly dense type plus numerous play aids, cards, 40 page scenario book, 12 page reference guide ,increasing the number of counters more than ten fold plus a map that looks about 4ft square.
At its core is the Battle For Moscow is very simple hex and counter game. Movement points, attack & defence ratings, throw in Zoc’s, Russian Campaign style airstrikes, a CRT its all very familiar ground.
Chadwick got this to work beautifully with the basic rule set at lower scales. Simply put, it played like a dream. All the players attention was on decisions and dice, the rules were light and logical enough to be kept in the head of a child as it was originally an introductory wargames set, this was recently demonstrated by my son who at 11 played Battle for Moscow with me and mastered the game with ease.
So my hope is this be another Third World War . In that game Chadwick made a playable monster. It wasnt light by any means but achieved a lot through simple mechanics, the air war rules in that game are sublime for example. Of course thats my hope, this could be a chrome burdened mess ruining a simple game, we shall see.
Chadwick rarely lets me down though and when he is on form he is truly on form.
