I'm having fun with this game, but I feel like I'm not getting very far. Any beginner's tips? Are you guys playing on normal difficulty or easy?
You don't want to play on easy as you don't get any achievement(well most of them don't work, some do), so you can't unlock classes and items. It takes a bit to get used to, generally you want to not waste time, you should try to complete levels in about 5mins, you can start slacking once you get past level 4 as at that point it doesn't make much of a difference anyway.
In level 1, you should try to find the teleporter asap, see if there's items you want on the way in the ones you can see, or large chests. If you find many item stuff and they're not too far from the teleporter, you can farm mobs for a couple of minutes to get enough gold, then start the teleporter and go open the chests during the countdown so you don't waste time. Level 2-4 you just want to rush the teleporter, the mobs get annoying and you'll spend a lot of time there which makes the next levels harder. Level 2s are alright but level 3 if you get the one with the water and you took too long it gets really fucking messy and level 4 if you get the lava level with too much time it's generally going to be very very hard to beat it cause the boss is all kinds of gay.
Level 5 and 6 though are always the same and I find the difficulty is about the same wether is 20mins or 30+ mins so that's when you want to make sure you open everything by farming and what not. For last level if you don't have the right items, I'd advise skipping mobs, just activate the doors then run away, hide on a ladder or just run back and forth avoiding shit while the doors open, and rush to the bridge, starting the final boss despawns all the mobs and he's fairly easy.
You should find the character that fits your playstyle too. The starting one is ok but not great unless you find a lot of proc damage items, as its base damage is kinda meh but he has super fast attackspeed. Bandit which you can get from completing level 3 is a nice alternative but again not super good, I'd say kinda average. The good characters you can unlock early are the engineer(use 40drones total, don't have to be in one game so it eventually unlocks even if you chain die on lvl 2) and Acrid which you need to fight and beat on level 3 if it's the water one(not the snow one), you can do him after the teleporter is done which makes it a ton easier. The 2 best classes are Huntress(need 15 monster log, takes a long time) and Mercenary(finish the game 5 times) so those you probably won't get right away. Can edit saves if you want though.
Thing though is levels aren't randomly generated, they're always the same. They have some stuff that can change(for example snow level has a bridge that sometimes is broken) but overall only your starting position changes, and there's like 4-5spots for teleporters so once you've played enough, you can find the teleporters quickly by checking usual spots. In terms of general tip, don't stand still, like ever. Also jump a lot. Jumping avoids most attacks and you can still fire while in the air with most stuff, it also lets you keep moving while you play the animation, if you attack while on the ground you'll generally stop. You can survive a lot better if you just always are running and jumping, in fact you should rarely facetank stuff unless you got godly RNG items.