What I mean is really big enemies which constitute a much bigger threat to the player. Even bigger than a horde of smaller enemies.
Ideally you want 4 classes of enemies
Small : About the size of the player, Dies in 1-2 hits, dangerous in groups, you already have these
Medium : Twice as big as the player, Dies in 6-8 hits, can be added in with small enemies
Large : 4x as large as player, Dies in 28-32 hits, very strong and should have little enemy presence with him
Killer : Friggin' huge, Dies in 120+ hits, no other enemies should be present when these are around
Adding these in pre-set waves can add a lot of solid structure to the levels, rather than feeling like a random swarm of enemies.
Ah! I see what you mean. The game have 6 enemies with different personality and difficulty. Changing size of the stronger enemies will visually make them look stronger too. That's a good idea!
These are the enemies:
Spitrrrr: Spawn often, normal health, moves slow, shoots slow, lowest score.
Splitr: Spawn less often, more health, moves faster, shoots faster, more score, spawning 2 new Spitrrrr enemies on destroy.
(noname): Spawn less often than Splitr, moves in normal speed, shoots fast lazerlike bullets every 1 sec, slower turning, more score than Splitr.
Bitr: Spawn less often than (noname), much health, runs fast towards player instead of shooting (player die on collision), more score than (noname).
Flankr: Spawn less often than Bitr, health like Splitr, moves in normal speed but is really slow at turning, more score than Bitr, front part is a shield and the butt is a weakpoint.
Bonus (goldbug): This one is like Bitr, but has more health, is faster and has the highest score value.
Also I want the game to spawn enemies randomly. You are not suppose to know who is attacking. Small enemies spawn all the time, but sometimes a bonus bug will spawn in the beginning etc.