This is not to say that it is perfect or the most hilarious thing ever (as some have suggested). The problem is that it doesn't have that many really good repeat characters. Some of those that make up the reoccurring creations are not able to carry the load because of them being rather one joke affairs, funny first time and maybe second time but not consistent enough. These reoccurring characters do still produce amusement though and there are exceptions to the rule that work really well. This puts a lot more pressure on the writers to deliver short, sharp ideas and it does produce some weaker moments. It is a matter of taste but I also found the fast editing and loud music between bits to be distracting and a little jarring but that is probably me getting older.
The cast deliver really well though and always put a lot into their sketches. Scheer is pretty good although relies on his geeky looks. I like Huebel because he has the look and build of a comedian playing it straight while still being funny. Ansari is probably the best of the three as he brings an energy and style to the show that makes him stick in the memory. Overall Human Giant is pretty funny stiff and I did quite enjoy it. I may check it out if they ever release a DVD of season 2 but I will temper that by saying that the lack of consistently good characters to match the creative one-offs does really limit it to being a solid sketch show rather than a really good or great one.