- * make blocks bounce again - ok
- * bonusblocks don't always bounce back to their original position (but stay a
- few pixels higher) - hopefully ok
- * it's impossible to go into passages that have exactly the size of tux,
- either reduce collision rectangle by DELTA or round collision coordinates to
- integers...
- ** implement 1up - ok
- ** implement star - ok
- * bring back the enemies
- - add activation again
- - make api simpler
- - implement jumpy - ok
- -* implement spiky - ok
- - implement snowball - ok