The lists:
Tyranid 1500:
Winged HT, +ST, +BS, 2 TL Devour, PsyScream
Walking HT, +ST, +BS, TL Devour, VenomC, PsyScream
3 x Elite Carnifex, +BS, 2 TL Devour
2 x 6 Genestealers, 4+ Save
14 Spinefist Gaunts
2 x Carnifex, +BS, +W, Barbed St, VenomC
3 x Zoanthropes, Warp Blast, PsyScream
Marines, Heed the wisdom of the ancients, stand alone 1500:
2 x Libby, Fury, Fear, Terminator armor
2 x 5 Terminators, 2 Assault Cannon
5 x 6 Las/Plas Tac squads
2 x Dreadnaught, Assault cannon
Marines player is graciously helping me train the nids for the hardest possible situations, we're playing Omega / Escalation, rolled mission, 25% cover.
Board setup has the usual terrain clumps on the corners, one very small tuft of trees (About the size of a fex) in the middle. Each edge has 1 corner with a large 4+ cover area building, and the other corner with a low 5+ cover set of hills. One edge gets a larger hill with a 4+ bunker inside, opposite edge gets a medium sized forest.
Mission rolled is recon (so far so good). Tyranids win roll for sides and pick the side with the forest, which is the best side of the two for lvl 3 area terrain. Marines win deployment, tyranids are holding everything in reserve. Marines load every tac squad onto the hill in the mid-left of his DZ. The hill has a bunker formation on top offering one full tac squad a 4+ cover save. Both terminator squads deploy to the far right on either side of his 4+ building.
Marines win first turn roll, force tyranids to go first.
Tyranid 1:
-Nothing on the table, whee!
Marine 1:
-Terminators advance 6"
Tyranid 2:
-Elite fex, Gaunts, Zoanthropes enter on the far left corner. I will be able to advance through the building (4+ cover sexiness) into his tac squad formations on the hill (probably around turn 4).
-No shooting.
Marine 2:
-Both dreads enter, one on far left corridor, on to the right of the tac squads. Neither can be pinpointed by antitank without taking a lot of heat from the tac-squads.
-One tac repositions further left to get a clearer line on the zoeys.
-Librarians fury the fex, gaunts, and zoeys. Fex takes a wound, gaunts pinned (no synapse, yay), one zoey takes a wound. Lone lascannon fires on a zoey, hits, 1 to wound (phew).
Tyranid 3:
-2 Elite fexes, and 2 heavy fexes enter directly in front of the terminator squads (intent is to make a wall for genestealers to advance on the terms), winged HT enters on the far left and hugs the building.
-Zoeys advance for clear shots on the repositioned tac squad, elite fex enters the building out of LOS from everything though.
-Zoeys kill 3 marines with warp blasts (5+ cover didn't save anyone), standoff against the terms brings 2 down (1 assault cannon dies from torrent of fire), and puts a wound on librarian.
Marine 3:
-Unwounded terms advance, wounded terms reposition to force anything firing on them to get into LOS of the tac squads. Dreads advance.
-Firing, left to right: Zoey is killed by lascannon fire. Heavy carnifex takes 2 wounds from assault cannons. 2 Furys sent at winged HT, no results.
Tyranid 4:
-Walking Tyrant and 1 squad of Genestealers enter on the far right to continue pushing against terms.
-Winged HT walks into the building, clear LOS and range on some Tac squads. Elite carnifex enters with him, same targets. Zoeys enter the building as well, still focused on the wounded tac squad. On the right, Elite fexes advance on the wounded terms, heavy fexes and walking HT face off the unwounded terms. Unwounded fex is shielding the wounded fex from the tac squads. Genestealers are hugging the forest the terms are hiding behind.
-Winged HT puts 10 results on the tac squad, 1 failed save. Babyfex can only reach a lascannon model, kills it. Zoeys whiff everything. Vs. the Terms, combined babyfex, heavy fex, and walking HT power brings the wounded squad down to a single term (libby dies horribly).
Marine 4:
-Dreads advance on the Winged HT in the building, last man standing forces the term to retreat, unwounded terms back up.
-4 lascannons, 3 plasma guns, 2 assault cannons into the winged HT. 2 Wounds. (4+ cover for the win?). Libby fury's into the genestealers, they are out of synapse and get pinned on an 11. Assault cannon puts a 3rd wound on the wounded fex.
Tyranid 5:
-Genestealers are still slacking (1 for reserve roll)
-Zoeys advance, winged HT moves to their spot deep enough to avoid most LOS except the tac and dread on the left. Babyfex advances. Spinegaunts man up and begin their rush for the DZ. On the right, elite fexes and walking HT move on the unwounded terminators, heavy fexes move towards the tac squads and now exposed dread.
-Zoeys immobilize the left dread. Winged HT wipes out a squad of 4. Babyfex puts some wounds on the big tac pile on the hill. Heavy fexes pen and destroy the right dread. Walking HT and Elite fexes kill an assault cannon, wound the libby, and kill a meatshield term.
Marine 5:
-Terms backpedal, remaining tac squads hold tight. 2 lascannons and 2 plasma (target priority with psychic choir forces one squad to shoot on the fex instead of the WHT) put 2 wounds on the elite fex in the building (he's now below half). Tac squad behind the immobilized dread fails to accomplish anything. Terms fire on the unwounded heavy fex, no result.
Tyanid 6:
-Last squad of stealers come in, running toward the larger term squad.
-Genestealers move on the lone term. Winged HT leaps out of cover to assault the immobilized Dread in his DZ. Spinegaunts running up the left side. Wounded bugs hide, unwounded advance.
-Genestealers fleet 5, enough for the charge on the lone term. Shooting brings another tac squad down on the hill, term squad is wiped.
-Genestealers eat the lone term for breakfast, consolidate towards tiny clump of trees. Winged HT eats the dread for breakfast, 3" sweep, can't base anything, hides in the wreckage.
Marine player calls it. He has 3 tac squads remaining. I have lost: 3 gaunts, 1 zoanthrope, 1 genestealer, 2 carnifexes below half. WHT would have died in turn 6 to rapidfire, but the outcome would not have changed.
Choosing the side really made the game for me. Had I been stuck with the other side, I would've eaten more tac squad fire on the advance, and had to probably cross the board corner to corner (see Astripps battle report of our last game for an example). Also the split front battle definitely worked in my favor. Bringing the weak first reserve rolls onto the left, and all the rest in on the far right on turn 3+ really baited the terms and HQs forward for recon, and then locked them into a seriously outgunned situation. Once the fight was on two fronts, and one of my fronts was tucked safely in 4+ cover, the game was decided.