You would have got a different answer if you had asked this question of an English lawyer about a trial at the Old Bailey in London.
In England, the old distinction between a minor offence ("misdemeanor") and a serious offence ("felony") was, in theory, swept away in 1971. But in reality, the distinction survives (slightly modified), albeit no longer with those names.
In terms of the appeals procedure, the difference may still be significant. Offences so minor as to be misdemeanors are no longer tried before a jury, and the right of appeal is extremely limited. For these offences, triable only before a Magistrate, there is normally only a fine on conviction, or a prison term not exceeding 6 months.
For a more serious charge, the right to a Jury trial is either automatic or is exercisable at the option of the accused. Where the trial is by judge and jury, the jury decide his guilt or innocence; and, because of that, an appeals court will usually (except in rare cases) refuse to substitute its own view of the facts for that taken by the jury.
The appeal court normally only deals with procedural issues, of which by far the most common is the type of application based on (some variation of) the allegation that the judge misdirected the jury. The accused then attempts to find some fault with the procedures which the judge adopted (perhaps alleging some procedural unfairness), or with his directions to the jury about the law.
In terms of shifting the blame from one defendant to another, this is relatively unlikely. The appeal court does not hear any evidence at all. It only considers legal arguments, and these generally pertain not to the evidence at the original trial, but usually only to the procedures used. If matters of evidence do arise, they might take the form of an objection to the judge's decision as to whether or not to permit a particular witness to give evidence (most commonly arising in relation to whether an expert was suitably qualified to give evidence).
In English law, the law of criminal evidence holds that a person cannot be convicted on the uncorroborated testimony of an accomplice. This most important restriction prevents any possibility of there being an attempt by one defendant to cast the blame onto another, at any stage in the proceedings.
The principal difficulty for the co-defendant who was acquitted at the trial is, in the event of an appeal against conviction by another defendant, that the double jeopardy rule was abolished by the last Labour government (i.e. fairly recently), and there have not (yet) been enough high-profile miscarriages of justice reported to have caused it to be restored.