The Cave

Requires The Time Traveler
Smells Like Team Spirit - Made all three characters smell like a dinosaur at once.
In the future version of the museum go to the cellar and head to the right until you reach the dinosaur exhibit.
Place your three characters in front of the dinosaur, push the green button and the achievement will unlock.

Fire In The Hole - 3 die by the Miner's hand.
When you meat the angry miner, he'll throw several things at you including dynamite.
Carefully approach with all three characters, make them stand on the same spot and wait for the dynamite to explode in range killing all three characters at once.

Well let's see, this achievement was easier than I thought.

I finished the new game, Lightspeed edition on the hardest difficulty and made a guide here:

https://steamcommunity.com/sharedfiles/filedetails/?id=1811299522

Well, its more of an account of what I did to win but Halcyon 6 (Classic) lacks a lot of things that Lightspeed has.

I still suggest you read it, as a lot of strategies also apply here except battle strategies because CLASSIC is way limited on your attack options.

For starters, Lightspeed DLC gives you use of an awesome Precursor ship, that ship alone could carry you the entire game, you dont have that here.

Lightspeed lets you customize starting and later-acquired Legendary officers so you can customize their epic power and choose between skills, you dont get that here.

Lightspeed has prestige skills on each officer, giving you up to six officer skills plus the ship skills in your arsenal. You only have 3 here.

Although it looks grim, its not that bad. Grand Admiral mode is waaaay easier than Emperor mode, the enemies dont have insane amounts of HP or damage in this difficulty compared to Emperor in Lightspeed.

The 3 starting skills of your officers are randomized and the key to a good run is two fold:

You need to start in a good system, at least 7 planetary systems that produce materials and 7 that produce dark matter.

Crew costs are also more expensive in CLASSIC and you should pay attention how to farm colonies for crew, you need them to restore mines and construct ships.

The second thing is rolling for two good starter officers and once the academy is built, round off your perfect ship fleet.

Since you are stuck with the epic powers of these officers, the game-breaking Bait and Switch stunning power of Lightspeed does not exist here..

I strongly suggest you pick the mechanic/engineer legendary officer as your epic, its swarm drones power helps a lot but you need to have two main engineer skills rolled on him, the one that taunts all enemies and gives you protection and a healing skill, the 3rd one is up to you.

If you dont get these two skills, quit the game and restart, you need these.

As for your second, you will want a tactical with Rally, Rally gives you a whooping 45% more damage and aim at level 3 and coupled with tactical ships 25% bonuses thats 70% more damage for at least 2 rounds, its awesome.

The third should be a science officer with the skill that gives quicken to an ally, you should always start a battle with Rally->Quicken your tactical->WeaponFocus.

He should also have an extra heal skill, a heal all would best so you can top off your health before destroying the final enemy ship.

After that, your entire fleet will have 70% more firepower, from here you can choose to use skills that hit all enemies or focus on the weakest one to take him out.

From there, its up to you, the threat of enemies in Grand Admiral is not as great as in Lightspeed's Emperor, so you should do fine, just focus on improving your fleet as fast as you can and do not destroy the spire until you are ready to go from Tier 3 to Tier 5 ships (Lvl 13 in your characters).

Hope this info helps!