Spent a decent amount of time on the preview event interacting with the Spike event and seeing some common questions being asked about it so I figured I'd make a post since I'm still at work and can't play.

What are spikes?
-New event that buffs monsters when they pick it up. Gives them increased HP, movement/atk speed and damage (I think damage was adjusted, correct me if I'm wrong)

Is this a permanent thing?
No. Looks like this event will run till the end of August.

Where to find spikes?
-Event is only CONSTRUCT type levels in the arcade at this time. Spikes do not spawn in any missions. There's different types of spike rarity based on the stratum you are in. You will need each type to craft to new diskguns from 2*-5*.
Depth 0-4 = Minute
Depth 5 -8 = Tiny
Depth 9-13 = Small
Depth 14-17 = Medium
Depth 18-22 = Large
Depth 23-28 = Huge

Additionally, spikes do drop from Starlight Cradle (sleep slime level) and deconstruction zones (credit to Bopp for pointing this out)

What can you do with spikes?
-There's a vendor in the Haven arcade where you can exchange it for forge crystals. There's also the new craftable diskgun that requires a lot of spikes to make.

Where are the new diskgun recipes?
-Basil. Recipes are double the price of normal recipes

How do spikes spawn?
-Spikes have a chance of spawning when enemies spawn in arcade. They will not spawn overtime when fighting enemies.

Does difficulty affect spike spawn rate?
-It does not.

Can only one person pick up spikes in a party?
-No spikes are shared across the party. If one person picks it up, everyone gets it.

How strong are spiked monsters?
-Monsters can stack up to 4 spikes, each giving more and more stats and heals them. Enemies can pick up additional spikes after the 4 stacks which will fire off a mortar attack similar to the gremlin mortars (you cannot pick up mortared shot spikes).

How is the new diskgun and how does it compare to mixer/orbit?
-It's a very strong weapon that does more damage than mixer/orbit on their neutral enemies due to its enhanced attacks where it does more damage on return hits (I think this is mandolin exclusive only but it might apply to other diskguns). It'll outperform mixer/orbit against gremlins and beasts due to being normal, but mixer and orbit will still better against elemental weakness monsters. Also has a chance to stun.

Tips for dealing with spike mobs.
-Poison is very good as it stops their healing when they pick up spikes.
-I'd prioritize trying to pick up spikes first before monsters can (they aggro pretty hard to them) and kill big threat enemies (healing gremlins, mecha knights, thwackers) since spikes make them way more difficult to deal with.

If you have any other questions just post here and I'll try to update or if others want to chime in that'd be appreciated.