The Good:Lighting the torches is fun, and a seriously cool mechanic. I'm definitely going to play around with that idea for my maps.
The second two rooms has engaging level design. The floor itself drew you forward, and gave you reason to keep goin.
Those glowing ticks. I don't know if they do anything special attack wise, but they glow! If you're going to stick with the dark theme, my lord, use those ticks! It's fun (in moderation) to not see the land, but still be able to see a swarm of glowing ticks charging at you through the unknown.
The Bad:Waaaayyyy too dark. That engaging level design I mentioned? It was rather inneffective because even though logically I knew it was there, I couldn't see it, so it felt exactly the same as the first two room. The darkness is fun at the very start, where it's new and exciting, but it quickly becomes "Okay, I'm just playing through blind (Or with my minimap)" Time to just spam attacks in front of me to kill everything" I would recommend raising the base light level to at least something visible, if you want to keep the all-over dark feel. Otherwise, ditch the darkness, and save it for particular areas.
On that note, the first two rooms are just boxes stuck on boxes. I understand it's a prison, however simply going through box after box is not fun. I would recommend switching it up a bit if you want to keep the strict prison layout, and have some cells be closed, others decayed and broken down, and perhaps a few that are connected by broken walls, leading into otherwise inaccessible cells.
The Arrow traps in the third room are seemingly pointless. I felt they added no significant threat, or puzzle to the gameplay of the level. I would recommend scrapping them entirely, or working them in to a puzzle. (The exception to this is the hallway at the top, where it has the timed arrows. That was fun, but altogether pointless. I would keep those arrows, but give the character a reason to brave the arrow traps, as opposed to fighting through the enemies to get there from the other side. As it is, going through the "shortcut" just gets you to more enemies)
The Ugly: (Things I just think you didn't intend, but are broken nonetheless)
In the third room, all the apples are stacked a million high. I never actually found an apple where it disappeared when I ate it, so they all filled me up to full health, and stayed there to heal me if I ever came back. The one time I found an orange it was actually worse, because it disappeared, only healing me for 25, instead of healing all the way to full.
In the first room, the secret room you can either enter through the glowing eyes, or break into from a cell is empty. Finding secrets is fun, finding empty secrets just makes you question what you're doing with your life.
Your map doesn't use the color cover doodads in the editor. You probably want to find these and use them, as it will make your interior spaces feel like they're inside (Creating a sharp contrast between walls that you can be on either side of, and walls where you're on the only side of).
Rooms one and three have no purpose. They have tons of enemies, but there aren't any keys, shops, or hordes of wealth to gather. They are entirely skippable as it currently is.
The ledges in the maps are placed poorly, so that they are aesthetically unappealing, just go through and re-position them until they don't look like they're all bunched up at the corners.
Over-arching themes and ways to improve:My only qualifications here are having played a lot of video-games, so take this with a grain of salt, but here are some general tips that you might want to follow to better your levels.
Always have a reason for everything. Those buttons at the beginning that open the doors right next to them? They're decent, in the sense that they allow you to bypass all the enemies in the cells if you want to, but then what reason is there for pushing them? An apple? Well, you're not fighting anything, so there's no need for that. Maybe try ditching the individual buttons, and at the furthest corner of the level, have one button to open all of the cells, letting loose the hordes of baddies, and allowing you to go in and collect that sweet sweet gold, and those precious bronze keys.
Give the player reasons to want to do things. As it was, I made it up to the fourth level (The one with tons of slimes and the elite skeletons thrown in) before I stopped, and I only made it there because I had a reason for playing (Helping out the custom level community, by giving the advice you're reading here). If it weren't for that, I probably would have made it half way through the first set of cell-blocks, in to the second set, saw it was the same, and then quit. Give reasons to continue. Oh, you want that 5-up? You want those stacks of fat cash, to purchase the upgrades from the vendors, hidden behind the silver doors? Well, now you've gotta find those keys, and that cash, you have to find the secret passages, to solve the puzzles, to get the rewards.
And don't just think this stops at the collectibles, apply this to everything. I already said above, give that arrow hallway a reason to exist, some perk to going through it, instead of around. The torches? Lighting them is hardly a worthwhile reason, since you move away from them seconds later, and you're back in to the dark. Make a room dark, but have three unlit torches, after the torches are lit, run a quick script and light the entire room, or reveal a secret, or do
something to make it worth my time.
You have some skills, that's for sure. The layout of the 3rd and 4th floors are better than anything I've managed to get done so far, just work on making sure it feel like a game, and I'll gladly give this another play once it's more finished.
Good luck!