Create engaging arenas that challenge players, avoiding monotony and spam of enemies through the use of pacing and randomization. Also a graphical suggestion.

If anybody could consider the Arena by any other nature, it would be the money making aspect. Arenas pack tons of enemies and give gracious rewards. However, the design feels lazy and flawed. It follows closely with the risk v. reward system, i.e. that the next portion of the arena will be more difficult, but for a great reward. There's nothing wrong with the meta-design of the arena system as viewed by me, but the implementation leaves a lot to be desired. I understand that it's supposed to be gladiatorial style, where the player is supposed to be challenged and finishing the the arena is supposed to give a feeling of elation. However:

1. Fights are monotonous. Each wave can be predicted. Roguelike mechanics address this, and by far this game is a perfect candidate.
2. The waves are spammy and the area is too small. Fighting 12 robots (I think that's the correct count) plus a few menders, fairies, etc. all packed into a small space isn't challenging, it's hard. Hardness is usually a sign of poor implementation, challenge is achieved from careful thought. Spam v. Waves or "Do we want to spawn all enemies now" vs. "Let's make them run the gauntlet"
3. The areas can violate Miller's Law. No person can keep up with everything happening at one time, and that's not a challenge. To keep with the second point, more waves vs. more enemies [at once].

My friends (around 3 or 4 regulars) and I are regular players. We all have elevator passes and do stratum runs nearly every day. The game's a blast. However, late stratum arenas are almost the coup de grâce of our runs. Entering one is nearly equivalent to a death sentence, not because it's too challenging, but because it punishes those that don't have certain builds that tend to be useful in arenas (gunslingers and the lot).

We've come up with a few ideas that would help out:

1. Have the last room spawn more waves as opposed to more enemies at a given time.
2. Engage the player through more random-like enemy spawning. We understand fire-themed arenas will spawn fire-themed enemies, however Wolvers/etc.->Lumbers->Polyps/Gun Puppies->Robots on the last room is mundane.
3. This is a graphical suggestion. The front gate that leads into each of the three rooms, can that be made more transparent while in the room? As a legally-but-not-fully-blind guy who suffers from vision that can make it difficult to discern objects, the gate can blend in with the enemies/objects and become a big trap.

So, I guess, feel free to rip apart my idea and tell me how it doesn't work. ;)