Poison Peril is different from Solo Brawl. In this mode you have only a limited number of transformations and you must complete the challenges given, e.g. 2x combo of lines of bats. Poison Peril is played not with coloured boxes but with skulls, bats, bones and coffins – as the
“death” mode of Solo Brawl. Any time you perform a wrong transformation, skulls on the planet will cough some more poison. The task here is to reach as many points as you can, i.e. complete as many challenges as you can.
However, there are some things I missed in the game. The truth is you get enormous statistics on your profile (how many won/lost games, how many times you’ve used which island, the highest score, the best combo, etc.) but I am not a statistics guy so it doesn’t help with anything. What I really miss is a campaign or a way to improve. You can only play individual matches with settings and modifiers as you want, which is a good choice but you have nothing to reach for, no goal to attain. 
Another drawback I see is in the level of your opponents as they are very strong and quick even when set on “easy”. You perform only a few minor transformations and they are already sending rockets at you against which you can’t possibly have any defence yet. Also, the mouse is very sensitive even after adjusting in Options, a good gaming mouse might help solve this.
Despite these facts it is still a very good game to play, with very good graphics for this kind of game. It’s a combination of 2D (the puzzle) and 3D (the world) environment. The sounds fit, music is fine – nothing special but it doesn’t annoy you even after playing the game for 2 hours straight. Overall it’s not a bad attempt but could use improvement in the next version.