Great job! In many ways this was better than the waves the original developers created. I would have enjoyed more mobs coming from the rear two entrances.

So I made a video about us winning Hardcore horde: https://www.youtube.com/watch?v=h0qRrs3u29M Check it out for strategies and I hope you enjoy it.

I beat it today with a friend on nightmare. I even recorded it.

This mod is so challenging and fun! If anyone is interested in seeing a co-op strategy, we pulled it off on nightmare mode: https://youtu.be/D6wGVYKZvEU

Captain Kawayama is a bit too easy. he should be a little harder to defeat.

Today a friend of mine and I completed hardcore horde. It took us 51 minutes and we left with 18 rift points. The torture is over, we can now rest.

Congratulations to @tanaya_yt to be the first in completing this in nightmare mode, I'm impressed!

(continued)
- my biggest weakness is I died quickly due to lack of defense trinket. So be careful in the last waves, as two hits from the big enemies can already finish you.

See the screenshot here for the traps layout. http://imgur.com/a/FQwIf

Just practice with apprentice or warlord first, before doing nightmare.
The only drawback using this strategy is it cannot break the completion time (39:40).
But I hope this is useful and any suggestion to improve this strategy is much appreciated.
Probably I will do it someday, without superaccurate crossbow mod, but I think it's just (near) impossible.
And finally, many thanks for Nokaubure, for creating this great level.

(continued)
In later waves like 20+, you should have enough mushrooms to tame every gnolls, and consider them as your reinforcement.
- after you have enough tars and mushrooms, next is floor portal. In my case, I use 4x4, which is sufficient to "loop" the enemies.
Concentrate on killing the easy enemies first (like the small orcs with wind, and ogre/fire ogre/troll).
The ice ogre and waterlord are difficult, needs at least 50 headshots, so they should be looped.
- On wave 14, 21, and later waves, there are a lot of earth lords. Just summon some dwarfs, to help clean up pesky earthlings.
- On wave 28, there are a lot of cyclop mages which you need to stay in the back or behind a pillar and shoot them from afar.
Most of the time, your dwarfs will die, but it's ok, as you can resurrect them.
- The final boss, Capt Kawayama is immune to almost everything, like crossbow stunt, tar trap, ice, mushroom. But he isn't immune to floor portal and explosion.

(continued)
- wind amulet, the most effective weapon again smaller orcs, just blow them away to their death, so you can focus on the giants
- in the early waves, lay out tars about 2/3 of the corridor.
- keep an eye on the minimap to check if there are trolls coming close. If so, kill them quickly with ice and headshot
- if bats are coming out, kill them quickly with ice and headshot (for the ice bat)
- gradually put boom barrel dispensers, especially on the walls near the north gate, and then on the pillars later.
- when you have enough money, (around wave 13), you can start laying spore mushrooms.
You need to learn the path of the gnolls, and place the spore mushrooms in strategic places, like near the west and east gate, and around the portal.
Usually in each wave, gnoll grenadiers are the first to come out, and they can be your best allies to help fight against the elementals. Just help them (with stunt, ice or wind), so they don't die quickly.

(sorry, due to 1000 char limits, I need to split the comments)

Ok, finally I figured out how to beat this level in nightmare solo :)
My setup is :
1. crossbow
2. ice
3. wind amulet
4. mana rage trinket
5. guardian trinket
6. tar
7. floor portal
8. spore mushroom
9. dwarf guardian
10. boom barrel dispenser. Remember also to upgrade the boom barrel to max
Thanks to Robonator for this tip, I find boom barrel is the most effective trap against horde of orcs.

The only cheat I use is superaccurate crossbow mod. Without this, I think it's impossible to kill them quickly. Unless you can headshot every single shot :)

Strategy:
- crossbow, my main weapon. With option headshot generates mana, I use this in combination with ice amulet to collect mana quickly. Just freeze a giant, and spam a headshot.
- ice amulet, to kill most of the giants quickly and air defense (bats)

As we all know, Robot Entertainment never fixed the connectivity issues. Instead they had to go on and make a half-assed crap game called "Orcs Must Die! Unchained". Anyways, I digress... - Thing is, third try broke due to connection issues in wave 24 or 27. Thanks to Robonator for trying with me and coming up with some killer tactics!

The problem is you don't have many combination of traps, only floor traps and/or barrel dispenser.

Second try, co-op with c0cOnUts, and the earth lords got us in wave 21. This mod is challenging.

First try, and I died in wave 17. It is truly intense!

Made it to wave 20 with a friend, said: 'Dude we might actually do it this time.' That was 2 waves before we got crushed... and exploded... and slashed... and crushed. But whatever. Great mod!!!

I unstall mods, but now it's very easy ! This mod is good ! Thank you.

Fantastic! Very Good level, new chalenge

Most of the enemies in this mod are weak against explosions, combine it with ice and there ya go: good damage.

It's trial and error. You need to find the combination of traps that deals more damage against a huge variety of mobs while being strong enough to deal with the gnolls.

I tried this solo on Warmage difficulty over and over and over again but i can't come further than wave 16 =P also trying this CO-OP makes this a little bit easier. Still haven't beat it though, maybe 1 day.......