What are some alternatives?
When comparing Toki Tori and Hollow Knight, you can also consider the following products
Braid - Resource planning & scheduling for professional services
Super Meat Boy - Let's start with what's the same: Dr. Fetus is still a jerk, gameplay is super challenging but fair, there are tight controls and great levels and you will die. a lot.
Secret Maryo Chronicles - Secret Maryo Chronicles is an Open Source two-dimensional platform game and is using an Open Graphics Library for the best possible graphic design and stock performance.
SuperTux - SuperTux is a classic 2D jump'n run sidescroller game in a style similar to the original Super...
Mutant Blobs Attack - Tales from Space: Mutant Blobs Attack is a sci-fi puzzle-platformer of CATACLYSMIC proportions.
Cave Story - Cave Story Tribute Site is a tribute fansite to a Japanese game called Doukutsu Monogatari and translated under the title Cave Story.