Heavy Barrel,
This game is super-bad-ass. an all-time favorite for me. Got to the end-boss without dieing, and then lost 2 lives because I forgot how to defeat him. In the end I made it to the end. Good time!
Black Widow,
Made it to level 50. I like how the game introduces new enemies further into the game - like the "Grenade bugs" and the bugs that split into 3 little dive-bomber bugs. After level 40, the game ramps up difficulty level to "insane".
best regards,
- dink