Heli-Cats has rank. For players new to shoot'em ups, rank is an internal mechanism that adjusts an arcade game's difficulty based on how a player is doing. It became a well-known concept with Battle Garegga back in 1996.
Unlike that game, Heli-Cats is nowhere as punishing or insane with its rank. There are only three things that affect rank here.
- Destroying an enemy - increases rank based on the enemy type
- Getting hit - reduces a lot of rank
- Using a bomb - reduces some rank
With these in mind, it is possible to control rank via several methods. For example:
- It may be a better strategy to avoid some enemies altogether, letting them go to slow down the increase. A good example is the weak drone, which comes in large batches.
- Since armor cannot go beyond 3 in arcade mode, it may be worth it to get hit at full armor before getting an extend every 400,000 score to reduce the rank instead of getting the 100,000 max armor extend bonus.
- Similarly, it may be worth using a bomb before picking up a bomb refill at full bombs, forgoing the 20,000 max bomb bonus. Bomb planning is a strategy that is easiest to learn.
Also, every mission in Arcade mode has an increasing rank cap that is higher than the one before it. This makes rank control more useful for later missions.
Most players who are still learning the game will not feel the rank at all if they are using continues to beat it. Skilled players going for 1CC, however, will definitely feel it from mission 4 onwards. Enemy bullet patterns are more intense and bullet speeds are faster. Enemy health remains unchanged.