Sorry but I am not sure what that has to do with power ups? A bonus stage just means adding length. As said it's a good game and I did realise already about chests but I didn't realise about bonus stage admittedly, but what I was clearly saying was the lack of weapon power ups and character abilities. Double jump. Faster movement. Knife with way more range and so on (like in bubble bobble when you get power up to blow faster bubbles or blow bubbles further, to use an analogy). So on.
And I will ABSOLUTELY buy the sequel then if that's the case! I still had fun playing through it and got my money's worth. As said I really like the mechanic of having to avoid enemies to get the knife, and I love the music, it fits the game perfectly. But for me cyborg force is king. it's BRUTALLY difficult and I haven't been able to finish it on one credit yet! Great game. Cheers bud.