Well, it’s not that hidden - you’ve found it! I’ve indulged in a little ramble about my fave GW game as well as a link about a newish game that has caught my eye....

AKA Epic: Armageddon (4th edition); Epic: 40,000 (3rd edition), Titan Legions (2nd edition) Space Marine (used for 2nd & 1st edition) and my favourite, Adeptus Titanicus (1st edition).
This is my favourite of all the GW games and I’d play any of the versions at the drop of a hat. It’s just the idea of it. Whole companies of Marines or Guard mustering for war - titans and gargants striding over the battlefield almost heedless of the lesser troops around them - hordes of troops dying with one blast of a gun. WH40K: Apocalypse is great, but for a better reflection of vast battles then this the game(s) to look at.
Fortunately I’ve had the chance recently to play a few games: 3rd edition rules against Trevor’s Space Wolves and 2nd edition against John’s Orks. Great games all.
The rules to the two best versions of the game are actually free. 2nd edition is now under fan control and is called NetEpic. (scroll down for version 5), this is the one for awesome titans and a detailed damage system for them. The current “official” version is here. The emphasis here is on the troops and tactical game play. Titans play a minor role but apart from that the system is the best yet. Model-wise (and 3rd ed rules), a lot of stuff can be had quite cheaply on Ebay. Just try under “Epic 40,000” or “Epic 40K” or “Epic Titans”. For more specific stuff try this guy.
Come and see me for a game when you want to see more than 5 super-heavies on a table at one time!

Legio Ignatum (Fire Wasps) deploy for battle.
Ork Great Gargant “Bonegrinda” rampages on, heedless of the allies in its path!
Crimson Fist Strike Force arrives.
Imperial Guard Baneblade Company hold the line.
Always on the lookout to spend more money than I have, and after a discussion which started about Mighty Empires and then moved on to naval combat in a fantasy setting I went looking to see the availability of Man’O’War or similar game and found Uncharted Seas. Might be worth a look.
There’s four fleets so far (Imperial Human, Orc, Dwarf and Dragon Lords) but it seems to cover the basics. There’s an Undead fleet amongst other coming soon.