Game title : Parasite Eve 2
Console : Play Station
Genre : Action RPG
Release date : 2000 - 2001

After you manage to beat the game once/Normal mode, there will be several modes available by the time you load your saved file
Here are them

1. Replay Mode
Difficulty : Easy
HP : Normal
MP : Normal
Enemy level : Easy
Supplies : Rich
PE Exp : Less expensive
Problematic points :
This is easier than the Normal mode that you played at the very first time of playing this game, so, as far as i know, no such problematic points
Bonus that you get after clearing the mode :
Some random bonus items that you will be able to buy in shops by the time you play the game again

2. Bounty Mode
Difficulty : Normal
HP : Normal
MP : Normal
Enemy Level : Stronger
Supplies : Normal
PE Exp : Normal
Problematic points :
Hidden Golem Soldiers that you will find since Akropolis Tower until Shelter. Pay attention that their attacks are stronger than the Normal Mode. All enemies's attacks are stronger also, so make sure you have enough wits to avoid their attacks. As for PE, try to have Max Healing, Metabolism, and Antibody. For additionals, try to max PE Lifedrain
Bonus that you will get after clearing the mode :
Scavenger Mode, Some random items

3. Scavenger Mode
Difficulty : Hard
HP : Normal
MP : Reduced to 10
Enemy level : Normal
Supplies : Poor
PE Exp : Slightly more expensive
Problematic points :
There're some bosses that might become your problem
- Cannon Mouth
Don't force yourself to beat him in 3 min to achieve a gun and a Good Ending. Make sure you avoid his flames and his catch.
- Giant ANMC controlled by Eve
Grenades are so few to be found, and Riot only cause small damage. As for my strategy, i use Shotgun and M4A1 Rifle. Prepare your Antibody and Healing whether he will cast Inferno, and you didn't managed to make him cancel that.
- Eve
Only one problematic point, her scream. Her scream will heal your MP, but if you don't cancel it quickly, it'll burn you and you will suffer Silence status and your MP will be at 0. To cancel it either use Riot, or Shotgun with R.Slug bullets.

I recommend that you follow Kyle's story when you were in Shelter so you can get Mongoose magnum gun and Maeda SP bullets from Rupert near the end of the story. Save that for Eve

Bonus that you will get after clearing the mode :
Nightmare mode, Random items

4. Nightmare Mode
Difficulty : Very Hard
HP : Reduced to 50
MP : Normal
Enemy Level : Very strong
Supplies : Very Poor
PE Exp : Significantly more expensive
Problematic points :
This is it, the hardest mode in the game. So, i'll list every boss since all of them are your problematic points
- Humanoid NMC
This very first boss can kill you directly by 2 bites in this mode. A good way to beat him, is using the table to block him to get near you, and you can shot him freely from across the table. Move strategically
- Number 9 (Akropolis Tower)
Raid him with MP5A5 that you got from a corpse. Keep your range from him. Use the electric cable and the Steam pipe to give additional damage, but make sure you do the timing right. Just make sure you raid him with bullets everytime you got a chance, and don;t ever being touched by his flaming sword attack, it can kill you directly if you were cornered, and if you were not in full-HP condition
- Spidey 1
Be agile, as he often use his Stealth ability. Don't ever stand in one place for too long, and shot him after he swing his claw. PE Plasma can help you to interrupt his Stealth
- Number 9 (Empty house)
Keep your range from him, launch Pyrokinesis after his slash
- Cannon Mouth
One of the most problematic boss. Same drill, don't force yourself to achive winning in 3 min. Avoid his catch at any cost, it could be very hurt. Also his flames. Stay at the corner between your room and the loft of the hotel, but avoid his flames
- Papa Horse phase 1
Try to lure him onto the Oil Barrels.
- Papa Horse phase 2
Be attentive. His stomp could be very hurt, avoid it at any cost. His charge attack could hurt also. Lure him onto Oil Barrels whether you haven't use them, or use dodge-and-attack strategy. I recommend that you have PE Metabolism or some Penicillin since his attacks cause Poison damage
- Spidey 2
Same drill with Spidey 1, but you should be more agile, and more strategic. If you can't do it, just run from him
- Big-Eater
Keep your range from him, and watch out of his Poison smoke and Sweat attacks
- Giant ANMC
Make sure you destroy the speakers first. Shoot him wild when you see he is fire-charging, and go away from him as far as you could, prepare your Antibody, since if you failed to cancel it, he will cast Inferno, and it's very hurt. Avoid his other attacks also
- Baby ANMC
Make sure you avoid Neck and Core's attack. One blast from his Core could instantly kill you. Don't force yourself to destroy all parts of his body. The quickest way is Head --> Core. If you were kinda interrupted with the Neck attack, kill it also
- Eve
Stay away from the bridge, and avoid all her charge attacks. Cancel her scream as quickly as possible, since it could inflict good damage to you later. If she made a copy of herself, make sure you defeat the copy first, and quickly. I recommend that you have PE Healing and Metabolism for this fight

Bonus that you will get after clearing the mode :
Secret ending, Random items (Most likely Hypervelocity gun, or Squall's Gunblade)