Nightmare Reaper
- If you hear wind, it means there is a secret or passage very close by.
- In the passages you enter through manhole covers, there can occasionally be multiple manhole covers to exit from. They are far less obvious than doors, so keep an eye out if it seems you've explored the whole map and have nowhere left to go.
- You can disable the minigames individually if there's one (or more) you don't want to play. It lets you just buy the upgrades without playing the associated levels (or in the case of the pokemon one, having to fight battles).
- The bonus multipliers you get for doing all of something in a level (killing all enemies, finding all secrets, etc.) add up quick, especially later on. You can see the number of enemies and treasures left in the level under your minimap so you won't have to guess.
- The events that spawn an orb that hits you with nasty effects have hints to help you find the orb. Lit up footprints on the floor and/or a glowing blue orb that shows you the general direction you need to go to find and kill it. Also, the one that spawns a screaming ghost head can have the damage avoided by turning your head away when the ghost pauses to scream.
- The elites with empty red circles over their head go off like a nuke when they die. Don't be anywhere near them if you can help it.