The game itself isn't too bad, but the it's so poorly optimized. My PC is above recommended requirements and it still lags for me. I don't have this issue with any other game. It makes the game not enjoyable, unfortunately.

The series of orcs must die got pretty bad with the release of OMD Deathtrap.

Level Design has a lot of flaws with trap spots.
For example:
you can place half a trap in another trap and lose money.
you can't place sometimes trap on walls or ceilings because the placing grid is wrong programmed.
Ceilings are far to high up to place traps, therefore around 5+ Traps are not usable, so you NEED to change your trap setup all the time which is pretty annoying.
Sentinels are mostly on idiotic spots.

Traps:
There is a little bit more balance in it, but there is definitely a good meta for especially difficulty 10.
You can't place sentinels anymore which is pretty sad, because i liked them in OMD 3.
Some of the upgrade that you can get are more like annoiance than an upgrade and the reroll costs alot.

Weapons:
Would be nice to change them, but you need to change your char to use another one. So less variety in use of weapons and more in characters.

Monsters:
Alot of Monsters, but not any elite monsters or minibosses which would be nice.
BUT the waves have especially in the lower difficulties not enough enemies spawning, because sometimes you are making coffee for waiting for the next monsters coming in. There is no pressure coming.
So are the monsters evading/attacking? or do i invite them?

Threads / Trap + Weapon + Skill Upgrades:
Would be nice to remove or disable them, but it is made so you can't make an OP Build, which also makes more useless, because you need sometimes to switch your traps.
To Unlock them is mostly easy enough, some of them are more a grind or luck to get certain conditions.

All in All it is a good game with friends to play, but sometimes a pain in the butt, because of the level design.

Hopefully the game gets more inspiration from OMD unchained and OMD 3.

had a bit of a rocky start - but the updates and balancing changes improved it quite a bit and now with the variaty of characters, the movement abilities and the option to build more barricades it's quite fun to play and gamble some skulls on how many missions you'll manage to complete :)