Quite a fun gameplay loop. Each different enemy has a cool gameplay mechanic, and I like how your chain length is tied to the hits you take and the bullets you shoot.
A couple nitpicks.
- The chain looks way longer than it is, so I'm often trying to move outward, and the chain visually looks long enough for me to do this, but I'm actually at the limit.
- It's possible to bank up distance and blow through several circles in a row without really having to deal with the different enemy types. In fact, unless you're constantly testing the chain length, it can happen by accident (I went straight from circle 3 to circle 7). A way to prevent this would help pacing and make sure your different enemy types get the screentime they deserve.
- I realized taking hits reduced chain length almost immediately, but it took a while to understand shooting also reduced the chain length. An easy way to fix that would be to have the projectiles actually be chain links to indicate they come from your chain.
- Magnet powerup was cool - did not understand what the other powerup(s?) did.
This was quite fun to play - well done!