Really great fun! Way too many deaths, but finally I just decided to aim for and stick to a build and it just worked. A dual-weilding pistol gunslinger gave me the win. The run that previously got me the furthest was also a gunslinger, though with SMGs, but I had major ammo issues before I could gain the benefits of Bulletstorm L2. With pistols I was always flush with ammo. Fully spec'd out, the Summoner was actually a rather trivial fight.

I'll have to try more builds, but I kinda wonder about the balance of the game.

Here's my character:

CheeseSun, level 15 Marine, defeated
The Summoner against all odds.
He survived for 10609 turns.
The run time was 2h 2m 44s.
He scored 4096 points.
He took MEDIUM risks.

CALLISTO L2 -> Mimir Habitat L1
Mimir Habitat L3 -> CalSec Central
CalSec Central - cleared
EUROPA L2 -> Conamara Chaos Biolabs L1
Conamara Chaos Biolabs L2 -> Containment Area
Containment Area - cleared
IO L2 -> Io Black Site L1
Io Black Site L2 -> Black Site Vaults
Black Site Vaults - cleared
BEYOND L2 -> Limbo
Limbo - cleared

Awards
CRI Star (bronze cluster) (+25)
* 25+ kills without taking damage
Explorer Ribbon (+50)
* Visited all encountered special levels
Conqueror Ribbon (+100)
* Completed all encountered special levels
JoviSec Silver Badge
* Win a game

He killed 421 out of 411 enemies.

5 former CRI soldiers
10 former soldiers
18 reavers
10 hellish soldiers
10 corrupted soldiers
24 turrets
3 exalted soldiers
3 exalted fiends
12 armored ravagers
14 plasma ravagers
5 siege ravagers
23 security drones
9 CRI bots
15 CRI marines
1 Summoner
33 fiends
30 fire fiends
8 toxic reavers
4 former CRI guards
2 CRI guards
11 former grunts
28 ravagers
22 former guards
29 archreavers
4 former CRI grunts
4 corrupted commandos
3 corrupted sergeants
5 CalSec sentrys
1 security bot
3 corrupted heavys
1 former commando
7 kerbeross
4 security sentrys
13 former sergeants
1 military drone
5 CalSec bots
5 exalted kerbeross
2 former CRI sergeants
6 cryobeross
3 toxibeross
11 rocket turrets
13 combat drones
14 cryoreavers
3 cybeross

Traits
Skilled L1
Hellrunner L2
Ironman L2
Reloader L2
Son of a Gun L2
Gunslinger L2
BULLETSTORM L3

Trait order
SoG->SoG->Hr->Gsl->Gsl->Rel->MBS->Rel->
MBS->Hr->Iro->MBS->Ski->Iro

Equipment
Slot #1 : AV3 9mm pistol PB
Slot #2 : AV2 9mm combat pistol PBA
Slot #3 : CRI plasma pistol PBA
Body : ENV armor PB
Utility : CRI pistol power control

Inventory
energy cell (x100)
energy cell (x100)
energy cell (x100)
energy cell (x100)
9mm ammo (x100)
9mm ammo (x100)
9mm ammo (x100)
9mm ammo (x16)
frag grenade (x2)
multitool (x4)
large medkit
large medkit

Congrats on this. Getting one of the speedrun medals is something I'm nowhere close to.

Out of curiosity, why Ski L1 as your second-to-last trait?


Edit: Haha, I just realized that I'd misread the time units in the title. That said, it's been a few months, but I think that's still faster than how long it took for me to get my first win.