So, what I'm getting is the different difficulties aren't really 'difficulties' right now, they just add more waves. Once I got over fumbling on the first map and accepted the way of just spamming long lines of traps, the higher difficulties are the same but with more waves and over time you need to make them go longer paths so you can spam more traps. The statuses are surprisingly ineffective seeming, the trip only seems to work once, the ice slow isn't very noticable and the damage multipliers just aren't noticable when enemies just instantly die to pretty much anything (and if your frontline is designed to clear out weaker enemies, the stronger enemies will be effectively weaker enemies by the time they reach your backline, so you can just spam spears until you run out of space and have to use fire)
I do like enemies instantly dying to various traps with slow cooldowns as opposed to the usual tower defence of wittling enemies down over time so I'm not suggesting to beef all the enemies up. I can barely tell what enemies are different beyond 'small enemy' and 'big enemy' though. Being able to spot distinct enemies and setting up combos (Like freeze -> barricade to funnel down a push trap walkway -> trip trap inside the push trap's range) would be good. Actually, traps with much larger ranges would really help make combos if you can balance it because right now, every trap can only really 'combo' with stuff right next to it, I really have to push enemies to walls to get wall traps to hit and the long-ways of the push trap is only maybe 2x as long as its width-ways. Also feels weird that the push traps seem to just do damage more than actually push enemies off of edges or herd them into areas.
Minor issues, I posted in thread an image that some enemies seem to get caught on corners (but respawn at start as likely expected) and sometimes I buy extra towers because the tower-buying thing hangs around and it took me a while to realize Q un-selects it. I keep forgetting to dismiss the top-left message because I never worked out how to turn off auto-start so I'm always rushing to build right from the start and just have that text over my screen the entire time.
I don't know what you plan to do next for content, but I'd like to see the traps specialize a bit more into certain roles and enemies specialize a bit more into certain roles before you add any more enemies/towers, that's basically the summary of my post.