I might have missed it but you can't die in this game right? All opposition is in the form of impeding your movement, kinda like the wonderful
RunMan: Race Around The World (but without the speed emphasis).
Exactly. The idea is that you cant die and as soon as you have finished an obstacle, its done. Trying to be a less frustrating but still challenging game.
If I remembered that correctly: how are you designing bosses in this context? Is it like a "you spent the whole level getting used to your temporary abilities, now show how you mastered them"-type deal?
It is kind of like that in all the boss fights, but they also have another layer of "how to not kill the player but still be challenging". I did think about how to achieve this a lot. The result is kind of mixed. Sadly, I have not implemented the "purest" versions of this in all the boss fights because of my scope and time frame.
Boss 1 - Spinning Pusher So in the first world you the temporary abilities are: Speed and Jump. This makes it perfect for a boss that is chasing you (or you chasing it, could have been the better way to go in hindsight).
So my initial idea was that you would be chased by this huge guy that is basically playing with you. And when they catch you, they pick you up and put you down on a previously reached "checkpoint". This would have been a very nice way to not kill you, but still punish you. It is basically the same thing, but visually, story wise and emotionally something totally different.
Anyway, this is not what I did, since I felt like I did not have the time to make this huge boss character with animations and all. So how it works now is that when the boss catches up to you, you get thrown backwards. The game fades to black and you get beamed down to your most recent checkpoint. The level has several checkpoints to make the experience less frustrating by not having to replay the whole level. It is technically the same thing as the initial idea, but presented, in my opinion, in a worse way. I have play tested it quite a lot and people generally does not react to it as "you died" which was the main goal.
Boss 2 - Big Fish New temporary abilities are: Flying and Slamming into the ground, wind or "diving" under water.
Here you have to make regular sized enemies chase you and trick them to get close enough to a big fish boss that will then eat them. This makes the big fish move. So here its more about coming up with the idea of feeding the fish with smaller fish and tricking them to get close enough. It is a bit more playful, includes other elements into the game and naturally removes the need for killing the player.
Boss 3 - X (not decided yet) This world only contains the final boss and does not introduce any new energies. The boss level has two parts. The first part where the player needs to progress and avoid getting hit by the projectiles fired at them. If you get hit, you restart at your last reached checkpoint (like the first boss). Then it has a final part where you need to figure out how to damage the boss and get the final super-energy.
Here the player gets a stronger sense of dying and failing than the first boss. It is the last thing you do in the game though, so I kind of like that it makes you feel more vulnerable. I will try to make the restart more natural though, so the player hopefully wont think of it as dying. Honestly though, I would have liked to have more bosses that plays out like the second one. More playful and with natural reasons for not dying.
Final I had other ideas like: Having the player steal the energy power ups from a boss that were protecting them by trying to push you away. And every time you stole an energy from them, they would move to another place, presenting a new challenge. Kind of a different twist on the second boss.
Another one was to have the player choose an energy/temporary ability and then perform different unique tasks with each one of them. The boss would be finished when all powers had been utilized in the correct way.
Sorry for this long long answer, but its something I have though a lot about and something that I feel has not been done too many times before, so its an interesting topic. Haha, its actually way longer than most posts so I guess your question hit a subject that's dear to me