What are some alternatives?
When comparing Downwell and SuperTux, you can also consider the following products
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.
Hollow Knight - Descend into the Dark Venture down into a beautiful, ruined world of insects and heroes
Super Phantom Cat - Retro-inspired 2D homage to 8 and 16 bit platform games.
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.
Minilens - Libre puzzle platformer for gravity-oblivious aliens
Agent Dash - Your mission, if you choose to accept it, is to destroy as many villainous bases as you can!